Storing low retention priority data in a dispersed storage network

ABSTRACT

A method begins by a processing module of a dispersed storage network (DSN) sending a set of low retention priority write requests to storage units of the DSN, where each low retention priority write request includes a low retention priority query. For each storage unit of the storage units that receives a low retention priority write request of the set of low retention priority write requests, the method continues with the processing module determining a low retention priority response regarding availability for storing low retention priority data based on current storage of low priority data objects and available memory for storing the low retention priority data. The method continues with the processing module sending the low retention priority response. When a threshold number of favorable low retention priority responses have been received, the method continues at the processing module facilitating storage of a low retention priority data object.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. §119(e) to U.S. Provisional Application No. 61/871,833,entitled “PRIORITIZING DATA RETENTION IN A DISPERSED STORAGE NETWORK”,filed Aug. 29, 2013, which is hereby incorporated herein by reference inits entirety and made part of the present U.S. Utility PatentApplication for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

NOT APPLICABLE

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

NOT APPLICABLE

BACKGROUND OF THE INVENTION

1. Technical Field Of the Invention

This invention relates generally to computer networks and moreparticularly to dispersed storage of data and distributed taskprocessing of data.

2. Description of Related Art

Computing devices are known to communicate data, process data, and/orstore data. Such computing devices range from wireless smart phones,laptops, tablets, personal computers (PC), work stations, and video gamedevices, to data centers that support millions of web searches, stocktrades, or on-line purchases every day. In general, a computing deviceincludes a central processing unit (CPU), a memory system, userinput/output interfaces, peripheral device interfaces, and aninterconnecting bus structure.

As is further known, a computer may effectively extend its CPU by using“cloud computing” to perform one or more computing functions (e.g., aservice, an application, an algorithm, an arithmetic logic function,etc.) on behalf of the computer. Further, for large services,applications, and/or functions, cloud computing may be performed bymultiple cloud computing resources in a distributed manner to improvethe response time for completion of the service, application, and/orfunction. For example, Hadoop is an open source software framework thatsupports distributed applications enabling application execution bythousands of computers.

In addition to cloud computing, a computer may use “cloud storage” aspart of its memory system. As is known, cloud storage enables a user,via its computer, to store files, applications, etc. on an Internetstorage system. The Internet storage system may include a RAID(redundant array of independent disks) system and/or a dispersed storagesystem that uses an error correction scheme to encode data for storage.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a distributedcomputing system in accordance with the present invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the present invention;

FIG. 3 is a diagram of an example of a distributed storage and taskprocessing in accordance with the present invention;

FIG. 4 is a schematic block diagram of an embodiment of an outbounddistributed storage and/or task (DST) processing in accordance with thepresent invention;

FIG. 5 is a logic diagram of an example of a method for outbound DSTprocessing in accordance with the present invention;

FIG. 6 is a schematic block diagram of an embodiment of a dispersederror encoding in accordance with the present invention;

FIG. 7 is a diagram of an example of a segment processing of thedispersed error encoding in accordance with the present invention;

FIG. 8 is a diagram of an example of error encoding and slicingprocessing of the dispersed error encoding in accordance with thepresent invention;

FIG. 9 is a diagram of an example of grouping selection processing ofthe outbound DST processing in accordance with the present invention;

FIG. 10 is a diagram of an example of converting data into slice groupsin accordance with the present invention;

FIG. 11 is a schematic block diagram of an embodiment of a DST executionunit in accordance with the present invention;

FIG. 12 is a schematic block diagram of an example of operation of a DSTexecution unit in accordance with the present invention;

FIG. 13 is a schematic block diagram of an embodiment of an inbounddistributed storage and/or task (DST) processing in accordance with thepresent invention;

FIG. 14 is a logic diagram of an example of a method for inbound DSTprocessing in accordance with the present invention;

FIG. 15 is a diagram of an example of de-grouping selection processingof the inbound DST processing in accordance with the present invention;

FIG. 16 is a schematic block diagram of an embodiment of a dispersederror decoding in accordance with the present invention;

FIG. 17 is a diagram of an example of de-slicing and error decodingprocessing of the dispersed error decoding in accordance with thepresent invention;

FIG. 18 is a diagram of an example of a de-segment processing of thedispersed error decoding in accordance with the present invention;

FIG. 19 is a diagram of an example of converting slice groups into datain accordance with the present invention;

FIG. 20 is a diagram of an example of a distributed storage within thedistributed computing system in accordance with the present invention;

FIG. 21 is a schematic block diagram of an example of operation ofoutbound distributed storage and/or task (DST) processing for storingdata in accordance with the present invention;

FIG. 22 is a schematic block diagram of an example of a dispersed errorencoding for the example of FIG. 21 in accordance with the presentinvention;

FIG. 23 is a diagram of an example of converting data into pillar slicegroups for storage in accordance with the present invention;

FIG. 24 is a schematic block diagram of an example of a storageoperation of a DST execution unit in accordance with the presentinvention;

FIG. 25 is a schematic block diagram of an example of operation ofinbound distributed storage and/or task (DST) processing for retrievingdispersed error encoded data in accordance with the present invention;

FIG. 26 is a schematic block diagram of an example of a dispersed errordecoding for the example of FIG. 25 in accordance with the presentinvention;

FIG. 27 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module storing a plurality ofdata and a plurality of task codes in accordance with the presentinvention;

FIG. 28 is a schematic block diagram of an example of the distributedcomputing system performing tasks on stored data in accordance with thepresent invention;

FIG. 29 is a schematic block diagram of an embodiment of a taskdistribution module facilitating the example of FIG. 28 in accordancewith the present invention;

FIG. 30 is a diagram of a specific example of the distributed computingsystem performing tasks on stored data in accordance with the presentinvention;

FIG. 31 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module storing data and taskcodes for the example of FIG. 30 in accordance with the presentinvention;

FIG. 32 is a diagram of an example of DST allocation information for theexample of FIG. 30 in accordance with the present invention;

FIGS. 33-38 are schematic block diagrams of the DSTN module performingthe example of FIG. 30 in accordance with the present invention;

FIG. 39 is a diagram of an example of combining result information intofinal results for the example of FIG. 30 in accordance with the presentinvention;

FIG. 40A is a schematic block diagram of an embodiment of a dispersedstorage network in accordance with the present invention;

FIG. 40B is a flowchart illustrating an example of prioritizing dataretention in accordance with the present invention;

FIG. 41A is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 41B is a flowchart illustrating an example of activating a newdispersed storage network vault in accordance with the presentinvention;

FIG. 42A is a schematic block diagram of another embodiment of adistributed storage and task execution unit in accordance with thepresent invention;

FIG. 42B is a flowchart illustrating an example of detecting aprocessing activity anomaly in accordance with the present invention;

FIG. 43A is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 43B is a flowchart illustrating an example of selecting activestorage units in accordance with the present invention;

FIG. 44 is a flowchart illustrating an example of enabling slicerebuilding in accordance with the present invention;

FIG. 45A is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 45B is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 45C is a flowchart illustrating an example of updatingde-duplication tracking data in accordance with the present invention;

FIG. 46A is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 46B is a flowchart illustrating an example of selecting dispersedstorage units within a storage pool in accordance with the presentinvention;

FIG. 46C is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 46D is a flowchart illustrating an example of selecting a storagepool in accordance with the present invention;

FIG. 47 is a flowchart illustrating an example of facilitating deletinga data object in accordance with the present invention;

FIG. 48A is a schematic block diagram of another embodiment of adispersed storage network in accordance with the present invention;

FIG. 48B is a flowchart illustrating an example of co-locatingassociated encoded data slices in accordance with the present invention;and

FIG. 48C is a flowchart illustrating another example of co-locatingassociated encoded data slices in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a distributedcomputing system 10 that includes a user device 12 and/or a user device14, a distributed storage and/or task (DST) processing unit 16, adistributed storage and/or task network (DSTN) managing unit 18, a DSTintegrity processing unit 20, and a distributed storage and/or tasknetwork (DSTN) module 22. The components of the distributed computingsystem 10 are coupled via a network 24, which may include one or morewireless and/or wire lined communication systems; one or more privateintranet systems and/or public internet systems; and/or one or morelocal area networks (LAN) and/or wide area networks (WAN).

The DSTN module 22 includes a plurality of distributed storage and/ortask (DST) execution units 36 that may be located at geographicallydifferent sites (e.g., one in Chicago, one in Milwaukee, etc.). Each ofthe DST execution units is operable to store dispersed error encodeddata and/or to execute, in a distributed manner, one or more tasks ondata. The tasks may be a simple function (e.g., a mathematical function,a logic function, an identify function, a find function, a search enginefunction, a replace function, etc.), a complex function (e.g.,compression, human and/or computer language translation, text-to-voiceconversion, voice-to-text conversion, etc.), multiple simple and/orcomplex functions, one or more algorithms, one or more applications,etc.

Each of the user devices 12-14, the DST processing unit 16, the DSTNmanaging unit 18, and the DST integrity processing unit 20 include acomputing core 26 and may be a portable computing device and/or a fixedcomputing device. A portable computing device may be a social networkingdevice, a gaming device, a cell phone, a smart phone, a personal digitalassistant, a digital music player, a digital video player, a laptopcomputer, a handheld computer, a tablet, a video game controller, and/orany other portable device that includes a computing core. A fixedcomputing device may be a personal computer (PC), a computer server, acable set-top box, a satellite receiver, a television set, a printer, afax machine, home entertainment equipment, a video game console, and/orany type of home or office computing equipment. User device 12 and DSTprocessing unit 16 are configured to include a DST client module 34.

With respect to interfaces, each interface 30, 32, and 33 includessoftware and/or hardware to support one or more communication links viathe network 24 indirectly and/or directly. For example, interfaces 30support a communication link (e.g., wired, wireless, direct, via a LAN,via the network 24, etc.) between user device 14 and the DST processingunit 16. As another example, interface 32 supports communication links(e.g., a wired connection, a wireless connection, a LAN connection,and/or any other type of connection to/from the network 24) between userdevice 12 and the DSTN module 22 and between the DST processing unit 16and the DSTN module 22. As yet another example, interface 33 supports acommunication link for each of the DSTN managing unit 18 and DSTintegrity processing unit 20 to the network 24.

The distributed computing system 10 is operable to support dispersedstorage (DS) error encoded data storage and retrieval, to supportdistributed task processing on received data, and/or to supportdistributed task processing on stored data. In general and with respectto DS error encoded data storage and retrieval, the distributedcomputing system 10 supports three primary operations: storagemanagement, data storage and retrieval (an example of which will bediscussed with reference to FIGS. 20-26), and data storage integrityverification. In accordance with these three primary functions, data canbe encoded, distributedly stored in physically different locations, andsubsequently retrieved in a reliable and secure manner. Such a system istolerant of a significant number of failures (e.g., up to a failurelevel, which may be greater than or equal to a pillar width minus adecode threshold minus one) that may result from individual storagedevice failures and/or network equipment failures without loss of dataand without the need for a redundant or backup copy. Further, the systemallows the data to be stored for an indefinite period of time withoutdata loss and does so in a secure manner (e.g., the system is veryresistant to attempts at hacking the data).

The second primary function (i.e., distributed data storage andretrieval) begins and ends with a user device 12-14. For instance, if asecond type of user device 14 has data 40 to store in the DSTN module22, it sends the data 40 to the DST processing unit 16 via its interface30. The interface 30 functions to mimic a conventional operating system(OS) file system interface (e.g., network file system (NFS), flash filesystem (FFS), disk file system (DFS), file transfer protocol (FTP),web-based distributed authoring and versioning (WebDAV), etc.) and/or ablock memory interface (e.g., small computer system interface (SCSI),internet small computer system interface (iSCSI), etc.). In addition,the interface 30 may attach a user identification code (ID) to the data40.

To support storage management, the DSTN managing unit 18 performs DSmanagement services. One such DS management service includes the DSTNmanaging unit 18 establishing distributed data storage parameters (e.g.,vault creation, distributed storage parameters, security parameters,billing information, user profile information, etc.) for a user device12-14 individually or as part of a group of user devices. For example,the DSTN managing unit 18 coordinates creation of a vault (e.g., avirtual memory block) within memory of the DSTN module 22 for a userdevice, a group of devices, or for public access and establishes pervault dispersed storage (DS) error encoding parameters for a vault. TheDSTN managing unit 18 may facilitate storage of DS error encodingparameters for each vault of a plurality of vaults by updating registryinformation for the distributed computing system 10. The facilitatingincludes storing updated registry information in one or more of the DSTNmodule 22, the user device 12, the DST processing unit 16, and the DSTintegrity processing unit 20.

The DS error encoding parameters (e.g. or dispersed storage error codingparameters) include data segmenting information (e.g., how many segmentsdata (e.g., a file, a group of files, a data block, etc.) is dividedinto), segment security information (e.g., per segment encryption,compression, integrity checksum, etc.), error coding information (e.g.,pillar width, decode threshold, read threshold, write threshold, etc.),slicing information (e.g., the number of encoded data slices that willbe created for each data segment); and slice security information (e.g.,per encoded data slice encryption, compression, integrity checksum,etc.).

The DSTN managing module 18 creates and stores user profile information(e.g., an access control list (ACL)) in local memory and/or withinmemory of the DSTN module 22. The user profile information includesauthentication information, permissions, and/or the security parameters.The security parameters may include encryption/decryption scheme, one ormore encryption keys, key generation scheme, and/or dataencoding/decoding scheme.

The DSTN managing unit 18 creates billing information for a particularuser, a user group, a vault access, public vault access, etc. Forinstance, the DSTN managing unit 18 tracks the number of times a useraccesses a private vault and/or public vaults, which can be used togenerate a per-access billing information. In another instance, the DSTNmanaging unit 18 tracks the amount of data stored and/or retrieved by auser device and/or a user group, which can be used to generate aper-data-amount billing information.

Another DS management service includes the DSTN managing unit 18performing network operations, network administration, and/or networkmaintenance. Network operations include authenticating user dataallocation requests (e.g., read and/or write requests), managingcreation of vaults, establishing authentication credentials for userdevices, adding/deleting components (e.g., user devices, DST executionunits, and/or DST processing units) from the distributed computingsystem 10, and/or establishing authentication credentials for DSTexecution units 36. Network administration includes monitoring devicesand/or units for failures, maintaining vault information, determiningdevice and/or unit activation status, determining device and/or unitloading, and/or determining any other system level operation thataffects the performance level of the system 10. Network maintenanceincludes facilitating replacing, upgrading, repairing, and/or expandinga device and/or unit of the system 10.

To support data storage integrity verification within the distributedcomputing system 10, the DST integrity processing unit 20 performsrebuilding of ‘bad’ or missing encoded data slices. At a high level, theDST integrity processing unit 20 performs rebuilding by periodicallyattempting to retrieve/list encoded data slices, and/or slice names ofthe encoded data slices, from the DSTN module 22. For retrieved encodedslices, they are checked for errors due to data corruption, outdatedversion, etc. If a slice includes an error, it is flagged as a ‘bad’slice. For encoded data slices that were not received and/or not listed,they are flagged as missing slices. Bad and/or missing slices aresubsequently rebuilt using other retrieved encoded data slices that aredeemed to be good slices to produce rebuilt slices. The rebuilt slicesare stored in memory of the DSTN module 22. Note that the DST integrityprocessing unit 20 may be a separate unit as shown, it may be includedin the DSTN module 22, it may be included in the DST processing unit 16,and/or distributed among the DST execution units 36.

To support distributed task processing on received data, the distributedcomputing system 10 has two primary operations: DST (distributed storageand/or task processing) management and DST execution on received data(an example of which will be discussed with reference to FIGS. 3-19).With respect to the storage portion of the DST management, the DSTNmanaging unit 18 functions as previously described. With respect to thetasking processing of the DST management, the DSTN managing unit 18performs distributed task processing (DTP) management services. One suchDTP management service includes the DSTN managing unit 18 establishingDTP parameters (e.g., user-vault affiliation information, billinginformation, user-task information, etc.) for a user device 12-14individually or as part of a group of user devices.

Another DTP management service includes the DSTN managing unit 18performing DTP network operations, network administration (which isessentially the same as described above), and/or network maintenance(which is essentially the same as described above). Network operationsinclude, but are not limited to, authenticating user task processingrequests (e.g., valid request, valid user, etc.), authenticating resultsand/or partial results, establishing DTP authentication credentials foruser devices, adding/deleting components (e.g., user devices, DSTexecution units, and/or DST processing units) from the distributedcomputing system, and/or establishing DTP authentication credentials forDST execution units.

To support distributed task processing on stored data, the distributedcomputing system 10 has two primary operations: DST (distributed storageand/or task) management and DST execution on stored data. With respectto the DST execution on stored data, if the second type of user device14 has a task request 38 for execution by the DSTN module 22, it sendsthe task request 38 to the DST processing unit 16 via its interface 30.An example of DST execution on stored data will be discussed in greaterdetail with reference to FIGS. 27-39. With respect to the DSTmanagement, it is substantially similar to the DST management to supportdistributed task processing on received data.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (TO)controller 56, a peripheral component interconnect (PCI) interface 58,an IO interface module 60, at least one IO device interface module 62, aread only memory (ROM) basic input output system (BIOS) 64, and one ormore memory interface modules. The one or more memory interfacemodule(s) includes one or more of a universal serial bus (USB) interfacemodule 66, a host bus adapter (HBA) interface module 68, a networkinterface module 70, a flash interface module 72, a hard drive interfacemodule 74, and a DSTN interface module 76.

The DSTN interface module 76 functions to mimic a conventional operatingsystem (OS) file system interface (e.g., network file system (NFS),flash file system (FFS), disk file system (DFS), file transfer protocol(FTP), web-based distributed authoring and versioning (WebDAV), etc.)and/or a block memory interface (e.g., small computer system interface(SCSI), internet small computer system interface (iSCSI), etc.). TheDSTN interface module 76 and/or the network interface module 70 mayfunction as the interface 30 of the user device 14 of FIG. 1. Furthernote that the IO device interface module 62 and/or the memory interfacemodules may be collectively or individually referred to as IO ports.

FIG. 3 is a diagram of an example of the distributed computing systemperforming a distributed storage and task processing operation. Thedistributed computing system includes a DST (distributed storage and/ortask) client module 34 (which may be in user device 14 and/or in DSTprocessing unit 16 of FIG. 1), a network 24, a plurality of DSTexecution units 1-n that includes two or more DST execution units 36 ofFIG. 1 (which form at least a portion of DSTN module 22 of FIG. 1), aDST managing module (not shown), and a DST integrity verification module(not shown). The DST client module 34 includes an outbound DSTprocessing section 80 and an inbound DST processing section 82. Each ofthe DST execution units 1-n includes a controller 86, a processingmodule 84, memory 88, a DT (distributed task) execution module 90, and aDST client module 34.

In an example of operation, the DST client module 34 receives data 92and one or more tasks 94 to be performed upon the data 92. The data 92may be of any size and of any content, where, due to the size (e.g.,greater than a few Terabytes), the content (e.g., secure data, etc.),and/or task(s) (e.g., MIPS intensive), distributed processing of thetask(s) on the data is desired. For example, the data 92 may be one ormore digital books, a copy of a company's emails, a large-scale Internetsearch, a video security file, one or more entertainment video files(e.g., television programs, movies, etc.), data files, and/or any otherlarge amount of data (e.g., greater than a few Terabytes).

Within the DST client module 34, the outbound DST processing section 80receives the data 92 and the task(s) 94. The outbound DST processingsection 80 processes the data 92 to produce slice groupings 96. As anexample of such processing, the outbound DST processing section 80partitions the data 92 into a plurality of data partitions. For eachdata partition, the outbound DST processing section 80 dispersed storage(DS) error encodes the data partition to produce encoded data slices andgroups the encoded data slices into a slice grouping 96. In addition,the outbound DST processing section 80 partitions the task 94 intopartial tasks 98, where the number of partial tasks 98 may correspond tothe number of slice groupings 96.

The outbound DST processing section 80 then sends, via the network 24,the slice groupings 96 and the partial tasks 98 to the DST executionunits 1-n of the DSTN module 22 of FIG. 1. For example, the outbound DSTprocessing section 80 sends slice group 1 and partial task 1 to DSTexecution unit 1. As another example, the outbound DST processingsection 80 sends slice group #n and partial task #n to DST executionunit #n.

Each DST execution unit performs its partial task 98 upon its slicegroup 96 to produce partial results 102. For example, DST execution unit#1 performs partial task #1 on slice group #1 to produce a partialresult #1, for results. As a more specific example, slice group #1corresponds to a data partition of a series of digital books and thepartial task #1 corresponds to searching for specific phrases, recordingwhere the phrase is found, and establishing a phrase count. In this morespecific example, the partial result #1 includes information as to wherethe phrase was found and includes the phrase count.

Upon completion of generating their respective partial results 102, theDST execution units send, via the network 24, their partial results 102to the inbound DST processing section 82 of the DST client module 34.The inbound DST processing section 82 processes the received partialresults 102 to produce a result 104. Continuing with the specificexample of the preceding paragraph, the inbound DST processing section82 combines the phrase count from each of the DST execution units 36 toproduce a total phrase count. In addition, the inbound DST processingsection 82 combines the ‘where the phrase was found’ information fromeach of the DST execution units 36 within their respective datapartitions to produce ‘where the phrase was found’ information for theseries of digital books.

In another example of operation, the DST client module 34 requestsretrieval of stored data within the memory of the DST execution units 36(e.g., memory of the DSTN module). In this example, the task 94 isretrieve data stored in the memory of the DSTN module. Accordingly, theoutbound DST processing section 80 converts the task 94 into a pluralityof partial tasks 98 and sends the partial tasks 98 to the respective DSTexecution units 1-n.

In response to the partial task 98 of retrieving stored data, a DSTexecution unit 36 identifies the corresponding encoded data slices 100and retrieves them. For example, DST execution unit #1 receives partialtask #1 and retrieves, in response thereto, retrieved slices #1. The DSTexecution units 36 send their respective retrieved slices 100 to theinbound DST processing section 82 via the network 24.

The inbound DST processing section 82 converts the retrieved slices 100into data 92. For example, the inbound DST processing section 82de-groups the retrieved slices 100 to produce encoded slices per datapartition. The inbound DST processing section 82 then DS error decodesthe encoded slices per data partition to produce data partitions. Theinbound DST processing section 82 de-partitions the data partitions torecapture the data 92.

FIG. 4 is a schematic block diagram of an embodiment of an outbounddistributed storage and/or task (DST) processing section 80 of a DSTclient module 34 FIG. 1 coupled to a DSTN module 22 of a FIG. 1 (e.g., aplurality of n DST execution units 36) via a network 24. The outboundDST processing section 80 includes a data partitioning module 110, adispersed storage (DS) error encoding module 112, a grouping selectormodule 114, a control module 116, and a distributed task control module118.

In an example of operation, the data partitioning module 110 partitionsdata 92 into a plurality of data partitions 120. The number ofpartitions and the size of the partitions may be selected by the controlmodule 116 via control 160 based on the data 92 (e.g., its size, itscontent, etc.), a corresponding task 94 to be performed (e.g., simple,complex, single step, multiple steps, etc.), DS encoding parameters(e.g., pillar width, decode threshold, write threshold, segment securityparameters, slice security parameters, etc.), capabilities of the DSTexecution units 36 (e.g., processing resources, availability ofprocessing recourses, etc.), and/or as may be inputted by a user, systemadministrator, or other operator (human or automated). For example, thedata partitioning module 110 partitions the data 92 (e.g., 100Terabytes) into 100,000 data segments, each being 1 Gigabyte in size.Alternatively, the data partitioning module 110 partitions the data 92into a plurality of data segments, where some of data segments are of adifferent size, are of the same size, or a combination thereof.

The DS error encoding module 112 receives the data partitions 120 in aserial manner, a parallel manner, and/or a combination thereof. For eachdata partition 120, the DS error encoding module 112 DS error encodesthe data partition 120 in accordance with control information 160 fromthe control module 116 to produce encoded data slices 122. The DS errorencoding includes segmenting the data partition into data segments,segment security processing (e.g., encryption, compression,watermarking, integrity check (e.g., CRC), etc.), error encoding,slicing, and/or per slice security processing (e.g., encryption,compression, watermarking, integrity check (e.g., CRC), etc.). Thecontrol information 160 indicates which steps of the DS error encodingare active for a given data partition and, for active steps, indicatesthe parameters for the step. For example, the control information 160indicates that the error encoding is active and includes error encodingparameters (e.g., pillar width, decode threshold, write threshold, readthreshold, type of error encoding, etc.).

The grouping selector module 114 groups the encoded slices 122 of a datapartition into a set of slice groupings 96. The number of slicegroupings corresponds to the number of DST execution units 36 identifiedfor a particular task 94. For example, if five DST execution units 36are identified for the particular task 94, the group selecting modulegroups the encoded slices 122 of a data partition into five slicegroupings 96. The grouping selector module 114 outputs the slicegroupings 96 to the corresponding DST execution units 36 via the network24.

The distributed task control module 118 receives the task 94 andconverts the task 94 into a set of partial tasks 98. For example, thedistributed task control module 118 receives a task to find where in thedata (e.g., a series of books) a phrase occurs and a total count of thephrase usage in the data. In this example, the distributed task controlmodule 118 replicates the task 94 for each DST execution unit 36 toproduce the partial tasks 98. In another example, the distributed taskcontrol module 118 receives a task to find where in the data a firstphrase occurs, where in the data a second phrase occurs, and a totalcount for each phrase usage in the data. In this example, thedistributed task control module 118 generates a first set of partialtasks 98 for finding and counting the first phase and a second set ofpartial tasks for finding and counting the second phrase. Thedistributed task control module 118 sends respective first and/or secondpartial tasks 98 to each DST execution unit 36.

FIG. 5 is a logic diagram of an example of a method for outbounddistributed storage and task (DST) processing that begins at step 126where a DST client module receives data and one or more correspondingtasks. The method continues at step 128 where the DST client moduledetermines a number of DST units to support the task for one or moredata partitions. For example, the DST client module may determine thenumber of DST units to support the task based on the size of the data,the requested task, the content of the data, a predetermined number(e.g., user indicated, system administrator determined, etc.), availableDST units, capability of the DST units, and/or any other factorregarding distributed task processing of the data. The DST client modulemay select the same DST units for each data partition, may selectdifferent DST units for the data partitions, or a combination thereof.

The method continues at step 130 where the DST client module determinesprocessing parameters of the data based on the number of DST unitsselected for distributed task processing. The processing parametersinclude data partitioning information, DS encoding parameters, and/orslice grouping information. The data partitioning information includes anumber of data partitions, size of each data partition, and/ororganization of the data partitions (e.g., number of data blocks in apartition, the size of the data blocks, and arrangement of the datablocks). The DS encoding parameters include segmenting information,segment security information, error encoding information (e.g.,dispersed storage error encoding function parameters including one ormore of pillar width, decode threshold, write threshold, read threshold,generator matrix), slicing information, and/or per slice securityinformation. The slice grouping information includes informationregarding how to arrange the encoded data slices into groups for theselected DST units. As a specific example, if the DST client moduledetermines that five DST units are needed to support the task, then itdetermines that the error encoding parameters include a pillar width offive and a decode threshold of three.

The method continues at step 132 where the DST client module determinestask partitioning information (e.g., how to partition the tasks) basedon the selected DST units and data processing parameters. The dataprocessing parameters include the processing parameters and DST unitcapability information. The DST unit capability information includes thenumber of DT (distributed task) execution units, execution capabilitiesof each DT execution unit (e.g., MIPS capabilities, processing resources(e.g., quantity and capability of microprocessors, CPUs, digital signalprocessors, co-processor, microcontrollers, arithmetic logic circuitry,and/or and the other analog and/or digital processing circuitry),availability of the processing resources, memory information (e.g.,type, size, availability, etc.)), and/or any information germane toexecuting one or more tasks.

The method continues at step 134 where the DST client module processesthe data in accordance with the processing parameters to produce slicegroupings. The method continues at step 136 where the DST client modulepartitions the task based on the task partitioning information toproduce a set of partial tasks. The method continues at step 138 wherethe DST client module sends the slice groupings and the correspondingpartial tasks to respective DST units.

FIG. 6 is a schematic block diagram of an embodiment of the dispersedstorage (DS) error encoding module 112 of an outbound distributedstorage and task (DST) processing section. The DS error encoding module112 includes a segment processing module 142, a segment securityprocessing module 144, an error encoding module 146, a slicing module148, and a per slice security processing module 150. Each of thesemodules is coupled to a control module 116 to receive controlinformation 160 therefrom.

In an example of operation, the segment processing module 142 receives adata partition 120 from a data partitioning module and receivessegmenting information as the control information 160 from the controlmodule 116. The segmenting information indicates how the segmentprocessing module 142 is to segment the data partition 120. For example,the segmenting information indicates how many rows to segment the databased on a decode threshold of an error encoding scheme, indicates howmany columns to segment the data into based on a number and size of datablocks within the data partition 120, and indicates how many columns toinclude in a data segment 152. The segment processing module 142segments the data 120 into data segments 152 in accordance with thesegmenting information.

The segment security processing module 144, when enabled by the controlmodule 116, secures the data segments 152 based on segment securityinformation received as control information 160 from the control module116. The segment security information includes data compression,encryption, watermarking, integrity check (e.g., cyclic redundancy check(CRC), etc.), and/or any other type of digital security. For example,when the segment security processing module 144 is enabled, it maycompress a data segment 152, encrypt the compressed data segment, andgenerate a CRC value for the encrypted data segment to produce a securedata segment 154. When the segment security processing module 144 is notenabled, it passes the data segments 152 to the error encoding module146 or is bypassed such that the data segments 152 are provided to theerror encoding module 146.

The error encoding module 146 encodes the secure data segments 154 inaccordance with error correction encoding parameters received as controlinformation 160 from the control module 116. The error correctionencoding parameters (e.g., also referred to as dispersed storage errorcoding parameters) include identifying an error correction encodingscheme (e.g., forward error correction algorithm, a Reed-Solomon basedalgorithm, an online coding algorithm, an information dispersalalgorithm, etc.), a pillar width, a decode threshold, a read threshold,a write threshold, etc. For example, the error correction encodingparameters identify a specific error correction encoding scheme,specifies a pillar width of five, and specifies a decode threshold ofthree. From these parameters, the error encoding module 146 encodes adata segment 154 to produce an encoded data segment 156.

The slicing module 148 slices the encoded data segment 156 in accordancewith the pillar width of the error correction encoding parametersreceived as control information 160. For example, if the pillar width isfive, the slicing module 148 slices an encoded data segment 156 into aset of five encoded data slices. As such, for a plurality of encodeddata segments 156 for a given data partition, the slicing module outputsa plurality of sets of encoded data slices 158.

The per slice security processing module 150, when enabled by thecontrol module 116, secures each encoded data slice 158 based on slicesecurity information received as control information 160 from thecontrol module 116. The slice security information includes datacompression, encryption, watermarking, integrity check (e.g., CRC,etc.), and/or any other type of digital security. For example, when theper slice security processing module 150 is enabled, it compresses anencoded data slice 158, encrypts the compressed encoded data slice, andgenerates a CRC value for the encrypted encoded data slice to produce asecure encoded data slice 122. When the per slice security processingmodule 150 is not enabled, it passes the encoded data slices 158 or isbypassed such that the encoded data slices 158 are the output of the DSerror encoding module 112. Note that the control module 116 may beomitted and each module stores its own parameters.

FIG. 7 is a diagram of an example of a segment processing of a dispersedstorage (DS) error encoding module. In this example, a segmentprocessing module 142 receives a data partition 120 that includes 45data blocks (e.g., d1-d45), receives segmenting information (i.e.,control information 160) from a control module, and segments the datapartition 120 in accordance with the control information 160 to producedata segments 152. Each data block may be of the same size as other datablocks or of a different size. In addition, the size of each data blockmay be a few bytes to megabytes of data. As previously mentioned, thesegmenting information indicates how many rows to segment the datapartition into, indicates how many columns to segment the data partitioninto, and indicates how many columns to include in a data segment.

In this example, the decode threshold of the error encoding scheme isthree; as such the number of rows to divide the data partition into isthree. The number of columns for each row is set to 15, which is basedon the number and size of data blocks. The data blocks of the datapartition are arranged in rows and columns in a sequential order (i.e.,the first row includes the first 15 data blocks; the second row includesthe second 15 data blocks; and the third row includes the last 15 datablocks).

With the data blocks arranged into the desired sequential order, theyare divided into data segments based on the segmenting information. Inthis example, the data partition is divided into 8 data segments; thefirst 7 include 2 columns of three rows and the last includes 1 columnof three rows. Note that the first row of the 8 data segments is insequential order of the first 15 data blocks; the second row of the 8data segments in sequential order of the second 15 data blocks; and thethird row of the 8 data segments in sequential order of the last 15 datablocks. Note that the number of data blocks, the grouping of the datablocks into segments, and size of the data blocks may vary toaccommodate the desired distributed task processing function.

FIG. 8 is a diagram of an example of error encoding and slicingprocessing of the dispersed error encoding processing the data segmentsof FIG. 7. In this example, data segment 1 includes 3 rows with each rowbeing treated as one word for encoding. As such, data segment 1 includesthree words for encoding: word 1 including data blocks d1 and d2, word 2including data blocks d16 and d17, and word 3 including data blocks d31and d32. Each of data segments 2-7 includes three words where each wordincludes two data blocks. Data segment 8 includes three words where eachword includes a single data block (e.g., d15, d30, and d45).

In operation, an error encoding module 146 and a slicing module 148convert each data segment into a set of encoded data slices inaccordance with error correction encoding parameters as controlinformation 160. More specifically, when the error correction encodingparameters indicate a unity matrix Reed-Solomon based encodingalgorithm, 5 pillars, and decode threshold of 3, the first three encodeddata slices of the set of encoded data slices for a data segment aresubstantially similar to the corresponding word of the data segment. Forinstance, when the unity matrix Reed-Solomon based encoding algorithm isapplied to data segment 1, the content of the first encoded data slice(DS1 _(—) d 1&2) of the first set of encoded data slices (e.g.,corresponding to data segment 1) is substantially similar to content ofthe first word (e.g., d1 & d2); the content of the second encoded dataslice (DS1 _(—) d 16&17) of the first set of encoded data slices issubstantially similar to content of the second word (e.g., d16 & d17);and the content of the third encoded data slice (DS1 _(—) d 31&32) ofthe first set of encoded data slices is substantially similar to contentof the third word (e.g., d31 & d32).

The content of the fourth and fifth encoded data slices (e.g., ES1_1 andES1_2) of the first set of encoded data slices include error correctiondata based on the first-third words of the first data segment. With suchan encoding and slicing scheme, retrieving any three of the five encodeddata slices allows the data segment to be accurately reconstructed.

The encoding and slices of data segments 2-7 yield sets of encoded dataslices similar to the set of encoded data slices of data segment 1. Forinstance, the content of the first encoded data slice (DS2 _(—) d 3&4)of the second set of encoded data slices (e.g., corresponding to datasegment 2) is substantially similar to content of the first word (e.g.,d3 & d4); the content of the second encoded data slice (DS2 _(—) d18&19) of the second set of encoded data slices is substantially similarto content of the second word (e.g., d18 & d19); and the content of thethird encoded data slice (DS2 _(—) d 33&34) of the second set of encodeddata slices is substantially similar to content of the third word (e.g.,d33 & d34). The content of the fourth and fifth encoded data slices(e.g., ES1_1 and ES1_2) of the second set of encoded data slicesincludes error correction data based on the first-third words of thesecond data segment.

FIG. 9 is a diagram of an example of grouping selection processing of anoutbound distributed storage and task (DST) processing in accordancewith group selection information as control information 160 from acontrol module. Encoded slices for data partition 122 are grouped inaccordance with the control information 160 to produce slice groupings96. In this example, a grouping selection module 114 organizes theencoded data slices into five slice groupings (e.g., one for each DSTexecution unit of a distributed storage and task network (DSTN) module).As a specific example, the grouping selection module 114 creates a firstslice grouping for a DST execution unit #1, which includes first encodedslices of each of the sets of encoded slices. As such, the first DSTexecution unit receives encoded data slices corresponding to data blocks1-15 (e.g., encoded data slices of contiguous data).

The grouping selection module 114 also creates a second slice groupingfor a DST execution unit #2, which includes second encoded slices ofeach of the sets of encoded slices. As such, the second DST executionunit receives encoded data slices corresponding to data blocks 16-30.The grouping selection module 114 further creates a third slice groupingfor DST execution unit #3, which includes third encoded slices of eachof the sets of encoded slices. As such, the third DST execution unitreceives encoded data slices corresponding to data blocks 31-45.

The grouping selection module 114 creates a fourth slice grouping forDST execution unit #4, which includes fourth encoded slices of each ofthe sets of encoded slices. As such, the fourth DST execution unitreceives encoded data slices corresponding to first error encodinginformation (e.g., encoded data slices of error coding (EC) data). Thegrouping selection module 114 further creates a fifth slice grouping forDST execution unit #5, which includes fifth encoded slices of each ofthe sets of encoded slices. As such, the fifth DST execution unitreceives encoded data slices corresponding to second error encodinginformation.

FIG. 10 is a diagram of an example of converting data 92 into slicegroups that expands on the preceding figures. As shown, the data 92 ispartitioned in accordance with a partitioning function 164 into aplurality of data partitions (1-x, where x is an integer greater than4). Each data partition (or chunkset of data) is encoded and groupedinto slice groupings as previously discussed by an encoding and groupingfunction 166. For a given data partition, the slice groupings are sentto distributed storage and task (DST) execution units. From datapartition to data partition, the ordering of the slice groupings to theDST execution units may vary.

For example, the slice groupings of data partition #1 is sent to the DSTexecution units such that the first DST execution receives first encodeddata slices of each of the sets of encoded data slices, whichcorresponds to a first continuous data chunk of the first data partition(e.g., refer to FIG. 9), a second DST execution receives second encodeddata slices of each of the sets of encoded data slices, whichcorresponds to a second continuous data chunk of the first datapartition, etc.

For the second data partition, the slice groupings may be sent to theDST execution units in a different order than it was done for the firstdata partition. For instance, the first slice grouping of the seconddata partition (e.g., slice group 2_1) is sent to the second DSTexecution unit; the second slice grouping of the second data partition(e.g., slice group 2_2) is sent to the third DST execution unit; thethird slice grouping of the second data partition (e.g., slice group2_3) is sent to the fourth DST execution unit; the fourth slice groupingof the second data partition (e.g., slice group 2_4, which includesfirst error coding information) is sent to the fifth DST execution unit;and the fifth slice grouping of the second data partition (e.g., slicegroup 2_5, which includes second error coding information) is sent tothe first DST execution unit.

The pattern of sending the slice groupings to the set of DST executionunits may vary in a predicted pattern, a random pattern, and/or acombination thereof from data partition to data partition. In addition,from data partition to data partition, the set of DST execution unitsmay change. For example, for the first data partition, DST executionunits 1-5 may be used; for the second data partition, DST executionunits 6-10 may be used; for the third data partition, DST executionunits 3-7 may be used; etc. As is also shown, the task is divided intopartial tasks that are sent to the DST execution units in conjunctionwith the slice groupings of the data partitions.

FIG. 11 is a schematic block diagram of an embodiment of a DST(distributed storage and/or task) execution unit that includes aninterface 169, a controller 86, memory 88, one or more DT (distributedtask) execution modules 90, and a DST client module 34. The memory 88 isof sufficient size to store a significant number of encoded data slices(e.g., thousands of slices to hundreds-of-millions of slices) and mayinclude one or more hard drives and/or one or more solid-state memorydevices (e.g., flash memory, DRAM, etc.).

In an example of storing a slice group, the DST execution modulereceives a slice grouping 96 (e.g., slice group #1) via interface 169.The slice grouping 96 includes, per partition, encoded data slices ofcontiguous data or encoded data slices of error coding (EC) data. Forslice group #1, the DST execution module receives encoded data slices ofcontiguous data for partitions #1 and #x (and potentially others between3 and x) and receives encoded data slices of EC data for partitions #2and #3 (and potentially others between 3 and x). Examples of encodeddata slices of contiguous data and encoded data slices of error coding(EC) data are discussed with reference to FIG. 9. The memory 88 storesthe encoded data slices of slice groupings 96 in accordance with memorycontrol information 174 it receives from the controller 86.

The controller 86 (e.g., a processing module, a CPU, etc.) generates thememory control information 174 based on a partial task(s) 98 anddistributed computing information (e.g., user information (e.g., userID, distributed computing permissions, data access permission, etc.),vault information (e.g., virtual memory assigned to user, user group,temporary storage for task processing, etc.), task validationinformation, etc.). For example, the controller 86 interprets thepartial task(s) 98 in light of the distributed computing information todetermine whether a requestor is authorized to perform the task 98, isauthorized to access the data, and/or is authorized to perform the taskon this particular data. When the requestor is authorized, thecontroller 86 determines, based on the task 98 and/or another input,whether the encoded data slices of the slice grouping 96 are to betemporarily stored or permanently stored. Based on the foregoing, thecontroller 86 generates the memory control information 174 to write theencoded data slices of the slice grouping 96 into the memory 88 and toindicate whether the slice grouping 96 is permanently stored ortemporarily stored.

With the slice grouping 96 stored in the memory 88, the controller 86facilitates execution of the partial task(s) 98. In an example, thecontroller 86 interprets the partial task 98 in light of thecapabilities of the DT execution module(s) 90. The capabilities includeone or more of MIPS capabilities, processing resources (e.g., quantityand capability of microprocessors, CPUs, digital signal processors,co-processor, microcontrollers, arithmetic logic circuitry, and/or anyother analog and/or digital processing circuitry), availability of theprocessing resources, etc. If the controller 86 determines that the DTexecution module(s) 90 have sufficient capabilities, it generates taskcontrol information 176.

The task control information 176 may be a generic instruction (e.g.,perform the task on the stored slice grouping) or a series ofoperational codes. In the former instance, the DT execution module 90includes a co-processor function specifically configured (fixed orprogrammed) to perform the desired task 98. In the latter instance, theDT execution module 90 includes a general processor topology where thecontroller stores an algorithm corresponding to the particular task 98.In this instance, the controller 86 provides the operational codes(e.g., assembly language, source code of a programming language, objectcode, etc.) of the algorithm to the DT execution module 90 forexecution.

Depending on the nature of the task 98, the DT execution module 90 maygenerate intermediate partial results 102 that are stored in the memory88 or in a cache memory (not shown) within the DT execution module 90.In either case, when the DT execution module 90 completes execution ofthe partial task 98, it outputs one or more partial results 102. Thepartial results 102 may also be stored in memory 88.

If, when the controller 86 is interpreting whether capabilities of theDT execution module(s) 90 can support the partial task 98, thecontroller 86 determines that the DT execution module(s) 90 cannotadequately support the task 98 (e.g., does not have the right resources,does not have sufficient available resources, available resources wouldbe too slow, etc.), it then determines whether the partial task 98should be fully offloaded or partially offloaded.

If the controller 86 determines that the partial task 98 should be fullyoffloaded, it generates DST control information 178 and provides it tothe DST client module 34. The DST control information 178 includes thepartial task 98, memory storage information regarding the slice grouping96, and distribution instructions. The distribution instructionsinstruct the DST client module 34 to divide the partial task 98 intosub-partial tasks 172, to divide the slice grouping 96 into sub-slicegroupings 170, and identify other DST execution units. The DST clientmodule 34 functions in a similar manner as the DST client module 34 ofFIGS. 3-10 to produce the sub-partial tasks 172 and the sub-slicegroupings 170 in accordance with the distribution instructions.

The DST client module 34 receives DST feedback 168 (e.g., sub-partialresults), via the interface 169, from the DST execution units to whichthe task was offloaded. The DST client module 34 provides thesub-partial results to the DST execution unit, which processes thesub-partial results to produce the partial result(s) 102.

If the controller 86 determines that the partial task 98 should bepartially offloaded, it determines what portion of the task 98 and/orslice grouping 96 should be processed locally and what should beoffloaded. For the portion that is being locally processed, thecontroller 86 generates task control information 176 as previouslydiscussed. For the portion that is being offloaded, the controller 86generates DST control information 178 as previously discussed.

When the DST client module 34 receives DST feedback 168 (e.g.,sub-partial results) from the DST executions units to which a portion ofthe task was offloaded, it provides the sub-partial results to the DTexecution module 90. The DT execution module 90 processes thesub-partial results with the sub-partial results it created to producethe partial result(s) 102.

The memory 88 may be further utilized to retrieve one or more of storedslices 100, stored results 104, partial results 102 when the DTexecution module 90 stores partial results 102 and/or results 104 andthe memory 88. For example, when the partial task 98 includes aretrieval request, the controller 86 outputs the memory control 174 tothe memory 88 to facilitate retrieval of slices 100 and/or results 104.

FIG. 12 is a schematic block diagram of an example of operation of adistributed storage and task (DST) execution unit storing encoded dataslices and executing a task thereon. To store the encoded data slices ofa partition 1 of slice grouping 1, a controller 86 generates writecommands as memory control information 174 such that the encoded slicesare stored in desired locations (e.g., permanent or temporary) withinmemory 88.

Once the encoded slices are stored, the controller 86 provides taskcontrol information 176 to a distributed task (DT) execution module 90.As a first step of executing the task in accordance with the taskcontrol information 176, the DT execution module 90 retrieves theencoded slices from memory 88. The DT execution module 90 thenreconstructs contiguous data blocks of a data partition. As shown forthis example, reconstructed contiguous data blocks of data partition 1include data blocks 1-15 (e.g., d1-d15).

With the contiguous data blocks reconstructed, the DT execution module90 performs the task on the reconstructed contiguous data blocks. Forexample, the task may be to search the reconstructed contiguous datablocks for a particular word or phrase, identify where in thereconstructed contiguous data blocks the particular word or phraseoccurred, and/or count the occurrences of the particular word or phraseon the reconstructed contiguous data blocks. The DST execution unitcontinues in a similar manner for the encoded data slices of otherpartitions in slice grouping 1. Note that with using the unity matrixerror encoding scheme previously discussed, if the encoded data slicesof contiguous data are uncorrupted, the decoding of them is a relativelystraightforward process of extracting the data.

If, however, an encoded data slice of contiguous data is corrupted (ormissing), it can be rebuilt by accessing other DST execution units thatare storing the other encoded data slices of the set of encoded dataslices of the corrupted encoded data slice. In this instance, the DSTexecution unit having the corrupted encoded data slices retrieves atleast three encoded data slices (of contiguous data and of error codingdata) in the set from the other DST execution units (recall for thisexample, the pillar width is 5 and the decode threshold is 3). The DSTexecution unit decodes the retrieved data slices using the DS errorencoding parameters to recapture the corresponding data segment. The DSTexecution unit then re-encodes the data segment using the DS errorencoding parameters to rebuild the corrupted encoded data slice. Oncethe encoded data slice is rebuilt, the DST execution unit functions aspreviously described.

FIG. 13 is a schematic block diagram of an embodiment of an inbounddistributed storage and/or task (DST) processing section 82 of a DSTclient module coupled to DST execution units of a distributed storageand task network (DSTN) module via a network 24. The inbound DSTprocessing section 82 includes a de-grouping module 180, a DS (dispersedstorage) error decoding module 182, a data de-partitioning module 184, acontrol module 186, and a distributed task control module 188. Note thatthe control module 186 and/or the distributed task control module 188may be separate modules from corresponding ones of outbound DSTprocessing section or may be the same modules.

In an example of operation, the DST execution units have completedexecution of corresponding partial tasks on the corresponding slicegroupings to produce partial results 102. The inbound DST processingsection 82 receives the partial results 102 via the distributed taskcontrol module 188. The inbound DST processing section 82 then processesthe partial results 102 to produce a final result, or results 104. Forexample, if the task was to find a specific word or phrase within data,the partial results 102 indicate where in each of the prescribedportions of the data the corresponding DST execution units found thespecific word or phrase. The distributed task control module 188combines the individual partial results 102 for the correspondingportions of the data into a final result 104 for the data as a whole.

In another example of operation, the inbound DST processing section 82is retrieving stored data from the DST execution units (i.e., the DSTNmodule). In this example, the DST execution units output encoded dataslices 100 corresponding to the data retrieval requests. The de-groupingmodule 180 receives retrieved slices 100 and de-groups them to produceencoded data slices per data partition 122. The DS error decoding module182 decodes, in accordance with DS error encoding parameters, theencoded data slices per data partition 122 to produce data partitions120.

The data de-partitioning module 184 combines the data partitions 120into the data 92. The control module 186 controls the conversion ofretrieve slices 100 into the data 92 using control signals 190 to eachof the modules. For instance, the control module 186 providesde-grouping information to the de-grouping module 180, provides the DSerror encoding parameters to the DS error decoding module 182, andprovides de-partitioning information to the data de-partitioning module184.

FIG. 14 is a logic diagram of an example of a method that is executableby distributed storage and task (DST) client module regarding inboundDST processing. The method begins at step 194 where the DST clientmodule receives partial results. The method continues at step 196 wherethe DST client module retrieves the task corresponding to the partialresults. For example, the partial results include header informationthat identifies the requesting entity, which correlates to the requestedtask.

The method continues at step 198 where the DST client module determinesresult processing information based on the task. For example, if thetask were to identify a particular word or phrase within the data, theresult processing information would indicate to aggregate the partialresults for the corresponding portions of the data to produce the finalresult. As another example, if the task were to count the occurrences ofa particular word or phrase within the data, results of processing theinformation would indicate to add the partial results to produce thefinal results. The method continues at step 200 where the DST clientmodule processes the partial results in accordance with the resultprocessing information to produce the final result or results.

FIG. 15 is a diagram of an example of de-grouping selection processingof an inbound distributed storage and task (DST) processing section of aDST client module. In general, this is an inverse process of thegrouping module of the outbound DST processing section of FIG. 9.Accordingly, for each data partition (e.g., partition #1), thede-grouping module retrieves the corresponding slice grouping from theDST execution units (EU) (e.g., DST 1-5).

As shown, DST execution unit #1 provides a first slice grouping, whichincludes the first encoded slices of each of the sets of encoded slices(e.g., encoded data slices of contiguous data of data blocks 1-15); DSTexecution unit #2 provides a second slice grouping, which includes thesecond encoded slices of each of the sets of encoded slices (e.g.,encoded data slices of contiguous data of data blocks 16-30); DSTexecution unit #3 provides a third slice grouping, which includes thethird encoded slices of each of the sets of encoded slices (e.g.,encoded data slices of contiguous data of data blocks 31-45); DSTexecution unit #4 provides a fourth slice grouping, which includes thefourth encoded slices of each of the sets of encoded slices (e.g., firstencoded data slices of error coding (EC) data); and DST execution unit#5 provides a fifth slice grouping, which includes the fifth encodedslices of each of the sets of encoded slices (e.g., first encoded dataslices of error coding (EC) data).

The de-grouping module de-groups the slice groupings (e.g., receivedslices 100) using a de-grouping selector 180 controlled by a controlsignal 190 as shown in the example to produce a plurality of sets ofencoded data slices (e.g., retrieved slices for a partition into sets ofslices 122). Each set corresponding to a data segment of the datapartition.

FIG. 16 is a schematic block diagram of an embodiment of a dispersedstorage (DS) error decoding module 182 of an inbound distributed storageand task (DST) processing section. The DS error decoding module 182includes an inverse per slice security processing module 202, ade-slicing module 204, an error decoding module 206, an inverse segmentsecurity module 208, a de-segmenting processing module 210, and acontrol module 186.

In an example of operation, the inverse per slice security processingmodule 202, when enabled by the control module 186, unsecures eachencoded data slice 122 based on slice de-security information receivedas control information 190 (e.g., the compliment of the slice securityinformation discussed with reference to FIG. 6) received from thecontrol module 186. The slice security information includes datadecompression, decryption, de-watermarking, integrity check (e.g., CRCverification, etc.), and/or any other type of digital security. Forexample, when the inverse per slice security processing module 202 isenabled, it verifies integrity information (e.g., a CRC value) of eachencoded data slice 122, it decrypts each verified encoded data slice,and decompresses each decrypted encoded data slice to produce sliceencoded data 158. When the inverse per slice security processing module202 is not enabled, it passes the encoded data slices 122 as the slicedencoded data 158 or is bypassed such that the retrieved encoded dataslices 122 are provided as the sliced encoded data 158.

The de-slicing module 204 de-slices the sliced encoded data 158 intoencoded data segments 156 in accordance with a pillar width of the errorcorrection encoding parameters received as control information 190 fromthe control module 186. For example, if the pillar width is five, thede-slicing module 204 de-slices a set of five encoded data slices intoan encoded data segment 156. The error decoding module 206 decodes theencoded data segments 156 in accordance with error correction decodingparameters received as control information 190 from the control module186 to produce secure data segments 154. The error correction decodingparameters include identifying an error correction encoding scheme(e.g., forward error correction algorithm, a Reed-Solomon basedalgorithm, an information dispersal algorithm, etc.), a pillar width, adecode threshold, a read threshold, a write threshold, etc. For example,the error correction decoding parameters identify a specific errorcorrection encoding scheme, specify a pillar width of five, and specifya decode threshold of three.

The inverse segment security processing module 208, when enabled by thecontrol module 186, unsecures the secured data segments 154 based onsegment security information received as control information 190 fromthe control module 186. The segment security information includes datadecompression, decryption, de-watermarking, integrity check (e.g., CRC,etc.) verification, and/or any other type of digital security. Forexample, when the inverse segment security processing module 208 isenabled, it verifies integrity information (e.g., a CRC value) of eachsecure data segment 154, it decrypts each verified secured data segment,and decompresses each decrypted secure data segment to produce a datasegment 152. When the inverse segment security processing module 208 isnot enabled, it passes the decoded data segment 154 as the data segment152 or is bypassed.

The de-segment processing module 210 receives the data segments 152 andreceives de-segmenting information as control information 190 from thecontrol module 186. The de-segmenting information indicates how thede-segment processing module 210 is to de-segment the data segments 152into a data partition 120. For example, the de-segmenting informationindicates how the rows and columns of data segments are to be rearrangedto yield the data partition 120.

FIG. 17 is a diagram of an example of de-slicing and error decodingprocessing of a dispersed error decoding module. A de-slicing module 204receives at least a decode threshold number of encoded data slices 158for each data segment in accordance with control information 190 andprovides encoded data 156. In this example, a decode threshold is three.As such, each set of encoded data slices 158 is shown to have threeencoded data slices per data segment. The de-slicing module 204 mayreceive three encoded data slices per data segment because an associateddistributed storage and task (DST) client module requested retrievingonly three encoded data slices per segment or selected three of theretrieved encoded data slices per data segment. As shown, which is basedon the unity matrix encoding previously discussed with reference to FIG.8, an encoded data slice may be a data-based encoded data slice (e.g.,DS1 _(—) d 1&d2) or an error code based encoded data slice (e.g.,ES3_1).

An error decoding module 206 decodes the encoded data 156 of each datasegment in accordance with the error correction decoding parameters ofcontrol information 190 to produce secured segments 154. In thisexample, data segment 1 includes 3 rows with each row being treated asone word for encoding. As such, data segment 1 includes three words:word 1 including data blocks d1 and d2, word 2 including data blocks d16and d17, and word 3 including data blocks d31 and d32. Each of datasegments 2-7 includes three words where each word includes two datablocks. Data segment 8 includes three words where each word includes asingle data block (e.g., d15, d30, and d45).

FIG. 18 is a diagram of an example of de-segment processing of aninbound distributed storage and task (DST) processing. In this example,a de-segment processing module 210 receives data segments 152 (e.g.,1-8) and rearranges the data blocks of the data segments into rows andcolumns in accordance with de-segmenting information of controlinformation 190 to produce a data partition 120. Note that the number ofrows is based on the decode threshold (e.g., 3 in this specific example)and the number of columns is based on the number and size of the datablocks.

The de-segmenting module 210 converts the rows and columns of datablocks into the data partition 120. Note that each data block may be ofthe same size as other data blocks or of a different size. In addition,the size of each data block may be a few bytes to megabytes of data.

FIG. 19 is a diagram of an example of converting slice groups into data92 within an inbound distributed storage and task (DST) processingsection. As shown, the data 92 is reconstructed from a plurality of datapartitions (1-x, where x is an integer greater than 4). Each datapartition (or chunk set of data) is decoded and re-grouped using ade-grouping and decoding function 212 and a de-partition function 214from slice groupings as previously discussed. For a given datapartition, the slice groupings (e.g., at least a decode threshold perdata segment of encoded data slices) are received from DST executionunits. From data partition to data partition, the ordering of the slicegroupings received from the DST execution units may vary as discussedwith reference to FIG. 10.

FIG. 20 is a diagram of an example of a distributed storage and/orretrieval within the distributed computing system. The distributedcomputing system includes a plurality of distributed storage and/or task(DST) processing client modules 34 (one shown) coupled to a distributedstorage and/or task processing network (DSTN) module, or multiple DSTNmodules, via a network 24. The DST client module 34 includes an outboundDST processing section 80 and an inbound DST processing section 82. TheDSTN module includes a plurality of DST execution units. Each DSTexecution unit includes a controller 86, memory 88, one or moredistributed task (DT) execution modules 90, and a DST client module 34.

In an example of data storage, the DST client module 34 has data 92 thatit desires to store in the DSTN module. The data 92 may be a file (e.g.,video, audio, text, graphics, etc.), a data object, a data block, anupdate to a file, an update to a data block, etc. In this instance, theoutbound DST processing module 80 converts the data 92 into encoded dataslices 216 as will be further described with reference to FIGS. 21-23.The outbound DST processing module 80 sends, via the network 24, to theDST execution units for storage as further described with reference toFIG. 24.

In an example of data retrieval, the DST client module 34 issues aretrieve request to the DST execution units for the desired data 92. Theretrieve request may address each DST executions units storing encodeddata slices of the desired data, address a decode threshold number ofDST execution units, address a read threshold number of DST executionunits, or address some other number of DST execution units. In responseto the request, each addressed DST execution unit retrieves its encodeddata slices 100 of the desired data and sends them to the inbound DSTprocessing section 82, via the network 24.

When, for each data segment, the inbound DST processing section 82receives at least a decode threshold number of encoded data slices 100,it converts the encoded data slices 100 into a data segment. The inboundDST processing section 82 aggregates the data segments to produce theretrieved data 92.

FIG. 21 is a schematic block diagram of an embodiment of an outbounddistributed storage and/or task (DST) processing section 80 of a DSTclient module coupled to a distributed storage and task network (DSTN)module (e.g., a plurality of DST execution units) via a network 24. Theoutbound DST processing section 80 includes a data partitioning module110, a dispersed storage (DS) error encoding module 112, a groupingselector module 114, a control module 116, and a distributed taskcontrol module 118.

In an example of operation, the data partitioning module 110 isby-passed such that data 92 is provided directly to the DS errorencoding module 112. The control module 116 coordinates the by-passingof the data partitioning module 110 by outputting a bypass 220 messageto the data partitioning module 110.

The DS error encoding module 112 receives the data 92 in a serialmanner, a parallel manner, and/or a combination thereof. The DS errorencoding module 112 DS error encodes the data in accordance with controlinformation 160 from the control module 116 to produce encoded dataslices 218. The DS error encoding includes segmenting the data 92 intodata segments, segment security processing (e.g., encryption,compression, watermarking, integrity check (e.g., CRC, etc.)), errorencoding, slicing, and/or per slice security processing (e.g.,encryption, compression, watermarking, integrity check (e.g., CRC,etc.)). The control information 160 indicates which steps of the DSerror encoding are active for the data 92 and, for active steps,indicates the parameters for the step. For example, the controlinformation 160 indicates that the error encoding is active and includeserror encoding parameters (e.g., pillar width, decode threshold, writethreshold, read threshold, type of error encoding, etc.).

The grouping selector module 114 groups the encoded slices 218 of thedata segments into pillars of slices 216. The number of pillarscorresponds to the pillar width of the DS error encoding parameters. Inthis example, the distributed task control module 118 facilitates thestorage request.

FIG. 22 is a schematic block diagram of an example of a dispersedstorage (DS) error encoding module 112 for the example of FIG. 21. TheDS error encoding module 112 includes a segment processing module 142, asegment security processing module 144, an error encoding module 146, aslicing module 148, and a per slice security processing module 150. Eachof these modules is coupled to a control module 116 to receive controlinformation 160 therefrom.

In an example of operation, the segment processing module 142 receivesdata 92 and receives segmenting information as control information 160from the control module 116. The segmenting information indicates howthe segment processing module is to segment the data. For example, thesegmenting information indicates the size of each data segment. Thesegment processing module 142 segments the data 92 into data segments152 in accordance with the segmenting information.

The segment security processing module 144, when enabled by the controlmodule 116, secures the data segments 152 based on segment securityinformation received as control information 160 from the control module116. The segment security information includes data compression,encryption, watermarking, integrity check (e.g., CRC, etc.), and/or anyother type of digital security. For example, when the segment securityprocessing module 144 is enabled, it compresses a data segment 152,encrypts the compressed data segment, and generates a CRC value for theencrypted data segment to produce a secure data segment. When thesegment security processing module 144 is not enabled, it passes thedata segments 152 to the error encoding module 146 or is bypassed suchthat the data segments 152 are provided to the error encoding module146.

The error encoding module 146 encodes the secure data segments inaccordance with error correction encoding parameters received as controlinformation 160 from the control module 116. The error correctionencoding parameters include identifying an error correction encodingscheme (e.g., forward error correction algorithm, a Reed-Solomon basedalgorithm, an information dispersal algorithm, etc.), a pillar width, adecode threshold, a read threshold, a write threshold, etc. For example,the error correction encoding parameters identify a specific errorcorrection encoding scheme, specifies a pillar width of five, andspecifies a decode threshold of three. From these parameters, the errorencoding module 146 encodes a data segment to produce an encoded datasegment.

The slicing module 148 slices the encoded data segment in accordancewith a pillar width of the error correction encoding parameters. Forexample, if the pillar width is five, the slicing module slices anencoded data segment into a set of five encoded data slices. As such,for a plurality of data segments, the slicing module 148 outputs aplurality of sets of encoded data slices as shown within encoding andslicing function 222 as described.

The per slice security processing module 150, when enabled by thecontrol module 116, secures each encoded data slice based on slicesecurity information received as control information 160 from thecontrol module 116. The slice security information includes datacompression, encryption, watermarking, integrity check (e.g., CRC,etc.), and/or any other type of digital security. For example, when theper slice security processing module 150 is enabled, it may compress anencoded data slice, encrypt the compressed encoded data slice, andgenerate a CRC value for the encrypted encoded data slice to produce asecure encoded data slice tweaking. When the per slice securityprocessing module 150 is not enabled, it passes the encoded data slicesor is bypassed such that the encoded data slices 218 are the output ofthe DS error encoding module 112.

FIG. 23 is a diagram of an example of converting data 92 into pillarslice groups utilizing encoding, slicing and pillar grouping function224 for storage in memory of a distributed storage and task network(DSTN) module. As previously discussed the data 92 is encoded and slicedinto a plurality of sets of encoded data slices; one set per datasegment. The grouping selection module organizes the sets of encodeddata slices into pillars of data slices. In this example, the DS errorencoding parameters include a pillar width of 5 and a decode thresholdof 3. As such, for each data segment, 5 encoded data slices are created.The grouping selection module takes the first encoded data slice of eachof the sets and forms a first pillar, which may be sent to the first DSTexecution unit. Similarly, the grouping selection module creates thesecond pillar from the second slices of the sets; the third pillar fromthe third slices of the sets; the fourth pillar from the fourth slicesof the sets; and the fifth pillar from the fifth slices of the set.

FIG. 24 is a schematic block diagram of an embodiment of a distributedstorage and/or task (DST) execution unit that includes an interface 169,a controller 86, memory 88, one or more distributed task (DT) executionmodules 90, and a DST client module 34. A computing core 26 may beutilized to implement the one or more DT execution modules 90 and theDST client module 34. The memory 88 is of sufficient size to store asignificant number of encoded data slices (e.g., thousands of slices tohundreds-of-millions of slices) and may include one or more hard drivesand/or one or more solid-state memory devices (e.g., flash memory, DRAM,etc.).

In an example of storing a pillar of slices 216, the DST execution unitreceives, via interface 169, a pillar of slices 216 (e.g., pillar #1slices). The memory 88 stores the encoded data slices 216 of the pillarof slices in accordance with memory control information 174 it receivesfrom the controller 86. The controller 86 (e.g., a processing module, aCPU, etc.) generates the memory control information 174 based ondistributed storage information (e.g., user information (e.g., user ID,distributed storage permissions, data access permission, etc.), vaultinformation (e.g., virtual memory assigned to user, user group, etc.),etc.). Similarly, when retrieving slices, the DST execution unitreceives, via interface 169, a slice retrieval request. The memory 88retrieves the slice in accordance with memory control information 174 itreceives from the controller 86. The memory 88 outputs the slice 100,via the interface 169, to a requesting entity.

FIG. 25 is a schematic block diagram of an example of operation of aninbound distributed storage and/or task (DST) processing section 82 forretrieving dispersed error encoded data 92. The inbound DST processingsection 82 includes a de-grouping module 180, a dispersed storage (DS)error decoding module 182, a data de-partitioning module 184, a controlmodule 186, and a distributed task control module 188. Note that thecontrol module 186 and/or the distributed task control module 188 may beseparate modules from corresponding ones of an outbound DST processingsection or may be the same modules.

In an example of operation, the inbound DST processing section 82 isretrieving stored data 92 from the DST execution units (i.e., the DSTNmodule). In this example, the DST execution units output encoded dataslices corresponding to data retrieval requests from the distributedtask control module 188. The de-grouping module 180 receives pillars ofslices 100 and de-groups them in accordance with control information 190from the control module 186 to produce sets of encoded data slices 218.The DS error decoding module 182 decodes, in accordance with the DSerror encoding parameters received as control information 190 from thecontrol module 186, each set of encoded data slices 218 to produce datasegments, which are aggregated into retrieved data 92. The datade-partitioning module 184 is by-passed in this operational mode via abypass signal 226 of control information 190 from the control module186.

FIG. 26 is a schematic block diagram of an embodiment of a dispersedstorage (DS) error decoding module 182 of an inbound distributed storageand task (DST) processing section. The DS error decoding module 182includes an inverse per slice security processing module 202, ade-slicing module 204, an error decoding module 206, an inverse segmentsecurity module 208, and a de-segmenting processing module 210. Thedispersed error decoding module 182 is operable to de-slice and decodeencoded slices per data segment 218 utilizing a de-slicing and decodingfunction 228 to produce a plurality of data segments that arede-segmented utilizing a de-segment function 230 to recover data 92.

In an example of operation, the inverse per slice security processingmodule 202, when enabled by the control module 186 via controlinformation 190, unsecures each encoded data slice 218 based on slicede-security information (e.g., the compliment of the slice securityinformation discussed with reference to FIG. 6) received as controlinformation 190 from the control module 186. The slice de-securityinformation includes data decompression, decryption, de-watermarking,integrity check (e.g., CRC verification, etc.), and/or any other type ofdigital security. For example, when the inverse per slice securityprocessing module 202 is enabled, it verifies integrity information(e.g., a CRC value) of each encoded data slice 218, it decrypts eachverified encoded data slice, and decompresses each decrypted encodeddata slice to produce slice encoded data. When the inverse per slicesecurity processing module 202 is not enabled, it passes the encodeddata slices 218 as the sliced encoded data or is bypassed such that theretrieved encoded data slices 218 are provided as the sliced encodeddata.

The de-slicing module 204 de-slices the sliced encoded data into encodeddata segments in accordance with a pillar width of the error correctionencoding parameters received as control information 190 from a controlmodule 186. For example, if the pillar width is five, the de-slicingmodule de-slices a set of five encoded data slices into an encoded datasegment. Alternatively, the encoded data segment may include just threeencoded data slices (e.g., when the decode threshold is 3).

The error decoding module 206 decodes the encoded data segments inaccordance with error correction decoding parameters received as controlinformation 190 from the control module 186 to produce secure datasegments. The error correction decoding parameters include identifyingan error correction encoding scheme (e.g., forward error correctionalgorithm, a Reed-Solomon based algorithm, an information dispersalalgorithm, etc.), a pillar width, a decode threshold, a read threshold,a write threshold, etc. For example, the error correction decodingparameters identify a specific error correction encoding scheme, specifya pillar width of five, and specify a decode threshold of three.

The inverse segment security processing module 208, when enabled by thecontrol module 186, unsecures the secured data segments based on segmentsecurity information received as control information 190 from thecontrol module 186. The segment security information includes datadecompression, decryption, de-watermarking, integrity check (e.g., CRC,etc.) verification, and/or any other type of digital security. Forexample, when the inverse segment security processing module is enabled,it verifies integrity information (e.g., a CRC value) of each securedata segment, it decrypts each verified secured data segment, anddecompresses each decrypted secure data segment to produce a datasegment 152. When the inverse segment security processing module 208 isnot enabled, it passes the decoded data segment 152 as the data segmentor is bypassed. The de-segmenting processing module 210 aggregates thedata segments 152 into the data 92 in accordance with controlinformation 190 from the control module 186.

FIG. 27 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module that includes aplurality of distributed storage and task (DST) execution units (#1through #n, where, for example, n is an integer greater than or equal tothree). Each of the DST execution units includes a DST client module 34,a controller 86, one or more DT (distributed task) execution modules 90,and memory 88.

In this example, the DSTN module stores, in the memory of the DSTexecution units, a plurality of DS (dispersed storage) encoded data(e.g., 1 through n, where n is an integer greater than or equal to two)and stores a plurality of DS encoded task codes (e.g., 1 through k,where k is an integer greater than or equal to two). The DS encoded datamay be encoded in accordance with one or more examples described withreference to FIGS. 3-19 (e.g., organized in slice groupings) or encodedin accordance with one or more examples described with reference toFIGS. 20-26 (e.g., organized in pillar groups). The data that is encodedinto the DS encoded data may be of any size and/or of any content. Forexample, the data may be one or more digital books, a copy of acompany's emails, a large-scale Internet search, a video security file,one or more entertainment video files (e.g., television programs,movies, etc.), data files, and/or any other large amount of data (e.g.,greater than a few Terabytes).

The tasks that are encoded into the DS encoded task code may be a simplefunction (e.g., a mathematical function, a logic function, an identifyfunction, a find function, a search engine function, a replace function,etc.), a complex function (e.g., compression, human and/or computerlanguage translation, text-to-voice conversion, voice-to-textconversion, etc.), multiple simple and/or complex functions, one or morealgorithms, one or more applications, etc. The tasks may be encoded intothe DS encoded task code in accordance with one or more examplesdescribed with reference to FIGS. 3-19 (e.g., organized in slicegroupings) or encoded in accordance with one or more examples describedwith reference to FIGS. 20-26 (e.g., organized in pillar groups).

In an example of operation, a DST client module of a user device or of aDST processing unit issues a DST request to the DSTN module. The DSTrequest may include a request to retrieve stored data, or a portionthereof, may include a request to store data that is included with theDST request, may include a request to perform one or more tasks onstored data, may include a request to perform one or more tasks on dataincluded with the DST request, etc. In the cases where the DST requestincludes a request to store data or to retrieve data, the client moduleand/or the DSTN module processes the request as previously discussedwith reference to one or more of FIGS. 3-19 (e.g., slice groupings)and/or 20-26 (e.g., pillar groupings). In the case where the DST requestincludes a request to perform one or more tasks on data included withthe DST request, the DST client module and/or the DSTN module processthe DST request as previously discussed with reference to one or more ofFIGS. 3-19.

In the case where the DST request includes a request to perform one ormore tasks on stored data, the DST client module and/or the DSTN moduleprocesses the DST request as will be described with reference to one ormore of FIGS. 28-39. In general, the DST client module identifies dataand one or more tasks for the DSTN module to execute upon the identifieddata. The DST request may be for a one-time execution of the task or foran on-going execution of the task. As an example of the latter, as acompany generates daily emails, the DST request may be to daily searchnew emails for inappropriate content and, if found, record the content,the email sender(s), the email recipient(s), email routing information,notify human resources of the identified email, etc.

FIG. 28 is a schematic block diagram of an example of a distributedcomputing system performing tasks on stored data. In this example, twodistributed storage and task (DST) client modules 1-2 are shown: thefirst may be associated with a user device and the second may beassociated with a DST processing unit or a high priority user device(e.g., high priority clearance user, system administrator, etc.). EachDST client module includes a list of stored data 234 and a list of taskscodes 236. The list of stored data 234 includes one or more entries ofdata identifying information, where each entry identifies data stored inthe DSTN module 22. The data identifying information (e.g., data ID)includes one or more of a data file name, a data file directory listing,DSTN addressing information of the data, a data object identifier, etc.The list of tasks 236 includes one or more entries of task codeidentifying information, when each entry identifies task codes stored inthe DSTN module 22. The task code identifying information (e.g., taskID) includes one or more of a task file name, a task file directorylisting, DSTN addressing information of the task, another type ofidentifier to identify the task, etc.

As shown, the list of data 234 and the list of tasks 236 are eachsmaller in number of entries for the first DST client module than thecorresponding lists of the second DST client module. This may occurbecause the user device associated with the first DST client module hasfewer privileges in the distributed computing system than the deviceassociated with the second DST client module. Alternatively, this mayoccur because the user device associated with the first DST clientmodule serves fewer users than the device associated with the second DSTclient module and is restricted by the distributed computing systemaccordingly. As yet another alternative, this may occur through norestraints by the distributed computing system, it just occurred becausethe operator of the user device associated with the first DST clientmodule has selected fewer data and/or fewer tasks than the operator ofthe device associated with the second DST client module.

In an example of operation, the first DST client module selects one ormore data entries 238 and one or more tasks 240 from its respectivelists (e.g., selected data ID and selected task ID). The first DSTclient module sends its selections to a task distribution module 232.The task distribution module 232 may be within a stand-alone device ofthe distributed computing system, may be within the user device thatcontains the first DST client module, or may be within the DSTN module22.

Regardless of the task distribution module's location, it generates DSTallocation information 242 from the selected task ID 240 and theselected data ID 238. The DST allocation information 242 includes datapartitioning information, task execution information, and/orintermediate result information. The task distribution module 232 sendsthe DST allocation information 242 to the DSTN module 22. Note that oneor more examples of the DST allocation information will be discussedwith reference to one or more of FIGS. 29-39.

The DSTN module 22 interprets the DST allocation information 242 toidentify the stored DS encoded data (e.g., DS error encoded data 2) andto identify the stored DS error encoded task code (e.g., DS errorencoded task code 1). In addition, the DSTN module 22 interprets the DSTallocation information 242 to determine how the data is to bepartitioned and how the task is to be partitioned. The DSTN module 22also determines whether the selected DS error encoded data 238 needs tobe converted from pillar grouping to slice grouping. If so, the DSTNmodule 22 converts the selected DS error encoded data into slicegroupings and stores the slice grouping DS error encoded data byoverwriting the pillar grouping DS error encoded data or by storing itin a different location in the memory of the DSTN module 22 (i.e., doesnot overwrite the pillar grouping DS encoded data).

The DSTN module 22 partitions the data and the task as indicated in theDST allocation information 242 and sends the portions to selected DSTexecution units of the DSTN module 22. Each of the selected DSTexecution units performs its partial task(s) on its slice groupings toproduce partial results. The DSTN module 22 collects the partial resultsfrom the selected DST execution units and provides them, as resultinformation 244, to the task distribution module. The result information244 may be the collected partial results, one or more final results asproduced by the DSTN module 22 from processing the partial results inaccordance with the DST allocation information 242, or one or moreintermediate results as produced by the DSTN module 22 from processingthe partial results in accordance with the DST allocation information242.

The task distribution module 232 receives the result information 244 andprovides one or more final results 104 therefrom to the first DST clientmodule. The final result(s) 104 may be result information 244 or aresult(s) of the task distribution module's processing of the resultinformation 244.

In concurrence with processing the selected task of the first DST clientmodule, the distributed computing system may process the selectedtask(s) of the second DST client module on the selected data(s) of thesecond DST client module. Alternatively, the distributed computingsystem may process the second DST client module's request subsequent to,or preceding, that of the first DST client module. Regardless of theordering and/or parallel processing of the DST client module requests,the second DST client module provides its selected data 238 and selectedtask 240 to a task distribution module 232. If the task distributionmodule 232 is a separate device of the distributed computing system orwithin the DSTN module, the task distribution modules 232 coupled to thefirst and second DST client modules may be the same module. The taskdistribution module 232 processes the request of the second DST clientmodule in a similar manner as it processed the request of the first DSTclient module.

FIG. 29 is a schematic block diagram of an embodiment of a taskdistribution module 232 facilitating the example of FIG. 28. The taskdistribution module 232 includes a plurality of tables it uses togenerate distributed storage and task (DST) allocation information 242for selected data and selected tasks received from a DST client module.The tables include data storage information 248, task storageinformation 250, distributed task (DT) execution module information 252,and task⇄sub-task mapping information 246.

The data storage information table 248 includes a data identification(ID) field 260, a data size field 262, an addressing information field264, distributed storage (DS) information 266, and may further includeother information regarding the data, how it is stored, and/or how itcan be processed. For example, DS encoded data #1 has a data ID of 1, adata size of AA (e.g., a byte size of a few Terabytes or more),addressing information of Addr_1_AA, and DS parameters of 3/5; SEG_1;and SLC_1. In this example, the addressing information may be a virtualaddress corresponding to the virtual address of the first storage word(e.g., one or more bytes) of the data and information on how tocalculate the other addresses, may be a range of virtual addresses forthe storage words of the data, physical addresses of the first storageword or the storage words of the data, may be a list of slice names ofthe encoded data slices of the data, etc. The DS parameters may includeidentity of an error encoding scheme, decode threshold/pillar width(e.g., 3/5 for the first data entry), segment security information(e.g., SEG_1), per slice security information (e.g., SLC_1), and/or anyother information regarding how the data was encoded into data slices.

The task storage information table 250 includes a task identification(ID) field 268, a task size field 270, an addressing information field272, distributed storage (DS) information 274, and may further includeother information regarding the task, how it is stored, and/or how itcan be used to process data. For example, DS encoded task #2 has a taskID of 2, a task size of XY, addressing information of Addr_2_XY, and DSparameters of 3/5; SEG_2; and SLC_2. In this example, the addressinginformation may be a virtual address corresponding to the virtualaddress of the first storage word (e.g., one or more bytes) of the taskand information on how to calculate the other addresses, may be a rangeof virtual addresses for the storage words of the task, physicaladdresses of the first storage word or the storage words of the task,may be a list of slices names of the encoded slices of the task code,etc. The DS parameters may include identity of an error encoding scheme,decode threshold/pillar width (e.g., 3/5 for the first data entry),segment security information (e.g., SEG_2), per slice securityinformation (e.g., SLC_2), and/or any other information regarding howthe task was encoded into encoded task slices. Note that the segmentand/or the per-slice security information include a type of encryption(if enabled), a type of compression (if enabled), watermarkinginformation (if enabled), and/or an integrity check scheme (if enabled).

The task⇄sub-task mapping information table 246 includes a task field256 and a sub-task field 258. The task field 256 identifies a taskstored in the memory of a distributed storage and task network (DSTN)module and the corresponding sub-task fields 258 indicates whether thetask includes sub-tasks and, if so, how many and if any of the sub-tasksare ordered. In this example, the task⇄sub-task mapping informationtable 246 includes an entry for each task stored in memory of the DSTNmodule (e.g., task 1 through task k). In particular, this exampleindicates that task 1 includes 7 sub-tasks; task 2 does not includesub-tasks, and task k includes r number of sub-tasks (where r is aninteger greater than or equal to two).

The DT execution module table 252 includes a DST execution unit ID field276, a DT execution module ID field 278, and a DT execution modulecapabilities field 280. The DST execution unit ID field 276 includes theidentity of DST units in the DSTN module. The DT execution module IDfield 278 includes the identity of each DT execution unit in each DSTunit. For example, DST unit 1 includes three DT executions modules(e.g., 1_1, 1_2, and 1_3). The DT execution capabilities field 280includes identity of the capabilities of the corresponding DT executionunit. For example, DT execution module 1_1 includes capabilities X,where X includes one or more of MIPS capabilities, processing resources(e.g., quantity and capability of microprocessors, CPUs, digital signalprocessors, co-processor, microcontrollers, arithmetic logic circuitry,and/or any other analog and/or digital processing circuitry),availability of the processing resources, memory information (e.g.,type, size, availability, etc.), and/or any information germane toexecuting one or more tasks.

From these tables, the task distribution module 232 generates the DSTallocation information 242 to indicate where the data is stored, how topartition the data, where the task is stored, how to partition the task,which DT execution units should perform which partial task on which datapartitions, where and how intermediate results are to be stored, etc. Ifmultiple tasks are being performed on the same data or different data,the task distribution module factors such information into itsgeneration of the DST allocation information.

FIG. 30 is a diagram of a specific example of a distributed computingsystem performing tasks on stored data as a task flow 318. In thisexample, selected data 92 is data 2 and selected tasks are tasks 1, 2,and 3. Task 1 corresponds to analyzing translation of data from onelanguage to another (e.g., human language or computer language); task 2corresponds to finding specific words and/or phrases in the data; andtask 3 corresponds to finding specific translated words and/or phrasesin translated data.

In this example, task 1 includes 7 sub-tasks: task 1_1—identifynon-words (non-ordered); task 1_2—identify unique words (non-ordered);task 1_3—translate (non-ordered); task 1_4—translate back (ordered aftertask 1_3); task 1_5—compare to ID errors (ordered after task 1-4); task1_6—determine non-word translation errors (ordered after task 1_5 and1_1); and task 1_7—determine correct translations (ordered after 1_5 and1_2). The sub-task further indicates whether they are an ordered task(i.e., are dependent on the outcome of another task) or non-order (i.e.,are independent of the outcome of another task). Task 2 does not includesub-tasks and task 3 includes two sub-tasks: task 3_1 translate; andtask 3_2 find specific word or phrase in translated data.

In general, the three tasks collectively are selected to analyze datafor translation accuracies, translation errors, translation anomalies,occurrence of specific words or phrases in the data, and occurrence ofspecific words or phrases on the translated data. Graphically, the data92 is translated 306 into translated data 282; is analyzed for specificwords and/or phrases 300 to produce a list of specific words and/orphrases 286; is analyzed for non-words 302 (e.g., not in a referencedictionary) to produce a list of non-words 290; and is analyzed forunique words 316 included in the data 92 (i.e., how many different wordsare included in the data) to produce a list of unique words 298. Each ofthese tasks is independent of each other and can therefore be processedin parallel if desired.

The translated data 282 is analyzed (e.g., sub-task 3_2) for specifictranslated words and/or phrases 304 to produce a list of specifictranslated words and/or phrases. The translated data 282 is translatedback 308 (e.g., sub-task 1_4) into the language of the original data toproduce re-translated data 284. These two tasks are dependent on thetranslate task (e.g., task 1_3) and thus must be ordered after thetranslation task, which may be in a pipelined ordering or a serialordering. The re-translated data 284 is then compared 310 with theoriginal data 92 to find words and/or phrases that did not translate(one way and/or the other) properly to produce a list of incorrectlytranslated words 294. As such, the comparing task (e.g., sub-task 1_5)310 is ordered after the translation 306 and re-translation tasks 308(e.g., sub-tasks 1_3 and 1_4).

The list of words incorrectly translated 294 is compared 312 to the listof non-words 290 to identify words that were not properly translatedbecause the words are non-words to produce a list of errors due tonon-words 292. In addition, the list of words incorrectly translated 294is compared 314 to the list of unique words 298 to identify unique wordsthat were properly translated to produce a list of correctly translatedwords 296. The comparison may also identify unique words that were notproperly translated to produce a list of unique words that were notproperly translated. Note that each list of words (e.g., specific wordsand/or phrases, non-words, unique words, translated words and/orphrases, etc.,) may include the word and/or phrase, how many times it isused, where in the data it is used, and/or any other informationrequested regarding a word and/or phrase.

FIG. 31 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module storing data and taskcodes for the example of FIG. 30. As shown, DS encoded data 2 is storedas encoded data slices across the memory (e.g., stored in memories 88)of DST execution units 1-5; the DS encoded task code 1 (of task 1) andDS encoded task 3 are stored as encoded task slices across the memory ofDST execution units 1-5; and DS encoded task code 2 (of task 2) isstored as encoded task slices across the memory of DST execution units3-7. As indicated in the data storage information table and the taskstorage information table of FIG. 29, the respective data/task has DSparameters of 3/5 for their decode threshold/pillar width; hencespanning the memory of five DST execution units.

FIG. 32 is a diagram of an example of distributed storage and task (DST)allocation information 242 for the example of FIG. 30. The DSTallocation information 242 includes data partitioning information 320,task execution information 322, and intermediate result information 324.The data partitioning information 320 includes the data identifier (ID),the number of partitions to split the data into, address information foreach data partition, and whether the DS encoded data has to betransformed from pillar grouping to slice grouping. The task executioninformation 322 includes tabular information having a taskidentification field 326, a task ordering field 328, a data partitionfield ID 330, and a set of DT execution modules 332 to use for thedistributed task processing per data partition. The intermediate resultinformation 324 includes tabular information having a name ID field 334,an ID of the DST execution unit assigned to process the correspondingintermediate result 336, a scratch pad storage field 338, and anintermediate result storage field 340.

Continuing with the example of FIG. 30, where tasks 1-3 are to bedistributedly performed on data 2, the data partitioning informationincludes the ID of data 2. In addition, the task distribution moduledetermines whether the DS encoded data 2 is in the proper format fordistributed computing (e.g., was stored as slice groupings). If not, thetask distribution module indicates that the DS encoded data 2 formatneeds to be changed from the pillar grouping format to the slicegrouping format, which will be done the by DSTN module. In addition, thetask distribution module determines the number of partitions to dividethe data into (e.g., 2_1 through 2 _(—) z) and addressing informationfor each partition.

The task distribution module generates an entry in the task executioninformation section for each sub-task to be performed. For example, task1_1 (e.g., identify non-words on the data) has no task ordering (i.e.,is independent of the results of other sub-tasks), is to be performed ondata partitions 2_1 through 2 _(—) z by DT execution modules 1_1, 2_1,3_1, 4_1, and 5_1. For instance, DT execution modules 1_1, 2_1, 3_1,4_1, and 5_1 search for non-words in data partitions 2_1 through 2 _(—)z to produce task 1_1 intermediate results (R1-1, which is a list ofnon-words). Task 1_2 (e.g., identify unique words) has similar taskexecution information as task 1_1 to produce task 1_2 intermediateresults (R1-2, which is the list of unique words).

Task 1_3 (e.g., translate) includes task execution information as beingnon-ordered (i.e., is independent), having DT execution modules 1_1,2_1, 3_1, 4_1, and 5_1 translate data partitions 2_1 through 2_4 andhaving DT execution modules 1_2, 2_2, 3_2, 4_2, and 5_2 translate datapartitions 2_5 through 2 _(—) z to produce task 1_3 intermediate results(R1-3, which is the translated data). In this example, the datapartitions are grouped, where different sets of DT execution modulesperform a distributed sub-task (or task) on each data partition group,which allows for further parallel processing.

Task 1_4 (e.g., translate back) is ordered after task 1_3 and is to beexecuted on task 1_3's intermediate result (e.g., R1-3_1) (e.g., thetranslated data). DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1 areallocated to translate back task 1_3 intermediate result partitionsR1-3_1 through R1-3_4 and DT execution modules 1_2, 2_2, 6_1, 7_1, and7_2 are allocated to translate back task 1_3 intermediate resultpartitions R1-3_5 through R1-3 _(—) z to produce task 1-4 intermediateresults (R1-4, which is the translated back data).

Task 1_5 (e.g., compare data and translated data to identify translationerrors) is ordered after task 1_4 and is to be executed on task 1_4'sintermediate results (R4-1) and on the data. DT execution modules 1_1,2_1, 3_1, 4_1, and 5_1 are allocated to compare the data partitions (2_1through 2 _(—) z) with partitions of task 1-4 intermediate resultspartitions R1-4_1 through R1-4 _(—) z to produce task 1_5 intermediateresults (R1-5, which is the list words translated incorrectly).

Task 1_6 (e.g., determine non-word translation errors) is ordered aftertasks 1_1 and 1_5 and is to be executed on tasks 1_1's and 1_5'sintermediate results (R1-1 and R1-5). DT execution modules 1_1, 2_1,3_1, 4_1, and 5_1 are allocated to compare the partitions of task 1_1intermediate results (R1-1_1 through R1-1 _(—) z) with partitions oftask 1-5 intermediate results partitions (R1-5_1 through R1-5 _(—) z) toproduce task 1_6 intermediate results (R1-6, which is the listtranslation errors due to non-words).

Task 1_7 (e.g., determine words correctly translated) is ordered aftertasks 1_2 and 1_5 and is to be executed on tasks 1_2's and 1_5'sintermediate results (R1-1 and R1-5). DT execution modules 1_2, 2_2,3_2, 4_2, and 5_2 are allocated to compare the partitions of task 1_2intermediate results (R1-2_1 through R1-2 _(—) z) with partitions oftask 1-5 intermediate results partitions (R1-5_1 through R1-5 _(—) z) toproduce task 1_7 intermediate results (R1-7, which is the list ofcorrectly translated words).

Task 2 (e.g., find specific words and/or phrases) has no task ordering(i.e., is independent of the results of other sub-tasks), is to beperformed on data partitions 2_1 through 2 _(—) z by DT executionmodules 3_1, 4_1, 5_1, 6_1, and 7_1. For instance, DT execution modules3_1, 4_1, 5_1, 6_1, and 7_1 search for specific words and/or phrases indata partitions 2_1 through 2 _(—) z to produce task 2 intermediateresults (R2, which is a list of specific words and/or phrases).

Task 3_2 (e.g., find specific translated words and/or phrases) isordered after task 1_3 (e.g., translate) is to be performed onpartitions R1-3_1 through R1-3 _(—) z by DT execution modules 1_2, 2_2,3_2, 4_2, and 5_2. For instance, DT execution modules 1_2, 2_2, 3_2,4_2, and 5_2 search for specific translated words and/or phrases in thepartitions of the translated data (R1-3_1 through R1-3 _(—) z) toproduce task 3_2 intermediate results (R3-2, which is a list of specifictranslated words and/or phrases).

For each task, the intermediate result information indicates which DSTunit is responsible for overseeing execution of the task and, if needed,processing the partial results generated by the set of allocated DTexecution units. In addition, the intermediate result informationindicates a scratch pad memory for the task and where the correspondingintermediate results are to be stored. For example, for intermediateresult R1-1 (the intermediate result of task 1_1), DST unit 1 isresponsible for overseeing execution of the task 1_1 and coordinatesstorage of the intermediate result as encoded intermediate result slicesstored in memory of DST execution units 1-5. In general, the scratch padis for storing non-DS encoded intermediate results and the intermediateresult storage is for storing DS encoded intermediate results.

FIGS. 33-38 are schematic block diagrams of the distributed storage andtask network (DSTN) module performing the example of FIG. 30. In FIG.33, the DSTN module accesses the data 92 and partitions it into aplurality of partitions 1-z in accordance with distributed storage andtask network (DST) allocation information. For each data partition, theDSTN identifies a set of its DT (distributed task) execution modules 90to perform the task (e.g., identify non-words (i.e., not in a referencedictionary) within the data partition) in accordance with the DSTallocation information. From data partition to data partition, the setof DT execution modules 90 may be the same, different, or a combinationthereof (e.g., some data partitions use the same set while other datapartitions use different sets).

For the first data partition, the first set of DT execution modules(e.g., 1_1, 2_1, 3_1, 4_1, and 5_1 per the DST allocation information ofFIG. 32) executes task 1_1 to produce a first partial result 102 ofnon-words found in the first data partition. The second set of DTexecution modules (e.g., 1_1, 2_1, 3_1, 4_1, and 5_1 per the DSTallocation information of FIG. 32) executes task 1_1 to produce a secondpartial result 102 of non-words found in the second data partition. Thesets of DT execution modules (as per the DST allocation information)perform task 1_1 on the data partitions until the “z” set of DTexecution modules performs task 1_1 on the “zth” data partition toproduce a “zth” partial result 102 of non-words found in the “zth” datapartition.

As indicated in the DST allocation information of FIG. 32, DST executionunit 1 is assigned to process the first through “zth” partial results toproduce the first intermediate result (R1-1), which is a list ofnon-words found in the data. For instance, each set of DT executionmodules 90 stores its respective partial result in the scratchpad memoryof DST execution unit 1 (which is identified in the DST allocation ormay be determined by DST execution unit 1). A processing module of DSTexecution 1 is engaged to aggregate the first through “zth” partialresults to produce the first intermediate result (e.g., R1_1). Theprocessing module stores the first intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 1.

DST execution unit 1 engages its DST client module to slice groupingbased DS error encode the first intermediate result (e.g., the list ofnon-words). To begin the encoding, the DST client module determineswhether the list of non-words is of a sufficient size to partition(e.g., greater than a Terabyte). If yes, it partitions the firstintermediate result (R1-1) into a plurality of partitions (e.g., R1-1_1through R1-1 _(—) m). If the first intermediate result is not ofsufficient size to partition, it is not partitioned.

For each partition of the first intermediate result, or for the firstintermediate result, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-5).

In FIG. 34, the DSTN module is performing task 1_2 (e.g., find uniquewords) on the data 92. To begin, the DSTN module accesses the data 92and partitions it into a plurality of partitions 1-z in accordance withthe DST allocation information or it may use the data partitions of task1_1 if the partitioning is the same. For each data partition, the DSTNidentifies a set of its DT execution modules to perform task 1_2 inaccordance with the DST allocation information. From data partition todata partition, the set of DT execution modules may be the same,different, or a combination thereof. For the data partitions, theallocated set of DT execution modules executes task 1_2 to produce apartial results (e.g., 1^(st) through “zth”) of unique words found inthe data partitions.

As indicated in the DST allocation information of FIG. 32, DST executionunit 1 is assigned to process the first through “zth” partial results102 of task 1_2 to produce the second intermediate result (R1-2), whichis a list of unique words found in the data 92. The processing module ofDST execution 1 is engaged to aggregate the first through “zth” partialresults of unique words to produce the second intermediate result. Theprocessing module stores the second intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 1.

DST execution unit 1 engages its DST client module to slice groupingbased DS error encode the second intermediate result (e.g., the list ofnon-words). To begin the encoding, the DST client module determineswhether the list of unique words is of a sufficient size to partition(e.g., greater than a Terabyte). If yes, it partitions the secondintermediate result (R1-2) into a plurality of partitions (e.g., R1-2_1through R1-2 _(—) m). If the second intermediate result is not ofsufficient size to partition, it is not partitioned.

For each partition of the second intermediate result, or for the secondintermediate results, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-5).

In FIG. 35, the DSTN module is performing task 1_3 (e.g., translate) onthe data 92. To begin, the DSTN module accesses the data 92 andpartitions it into a plurality of partitions 1-z in accordance with theDST allocation information or it may use the data partitions of task 1_1if the partitioning is the same. For each data partition, the DSTNidentifies a set of its DT execution modules to perform task 1_3 inaccordance with the DST allocation information (e.g., DT executionmodules 1_1, 2_1, 3_1, 4_1, and 5_1 translate data partitions 2_1through 2_4 and DT execution modules 1_2, 2_2, 3_2, 4_2, and 5_2translate data partitions 2_5 through 2 _(—) z). For the datapartitions, the allocated set of DT execution modules 90 executes task1_3 to produce partial results 102 (e.g., 1^(st) through “zth”) oftranslated data.

As indicated in the DST allocation information of FIG. 32, DST executionunit 2 is assigned to process the first through “zth” partial results oftask 1_3 to produce the third intermediate result (R1-3), which istranslated data. The processing module of DST execution 2 is engaged toaggregate the first through “zth” partial results of translated data toproduce the third intermediate result. The processing module stores thethird intermediate result as non-DS error encoded data in the scratchpadmemory or in another section of memory of DST execution unit 2.

DST execution unit 2 engages its DST client module to slice groupingbased DS error encode the third intermediate result (e.g., translateddata). To begin the encoding, the DST client module partitions the thirdintermediate result (R1-3) into a plurality of partitions (e.g., R1-3_1through R1-3 _(—) y). For each partition of the third intermediateresult, the DST client module uses the DS error encoding parameters ofthe data (e.g., DS parameters of data 2, which includes 3/5 decodethreshold/pillar width ratio) to produce slice groupings. The slicegroupings are stored in the intermediate result memory (e.g., allocatedmemory in the memories of DST execution units 2-6 per the DST allocationinformation).

As is further shown in FIG. 35, the DSTN module is performing task 1_4(e.g., retranslate) on the translated data of the third intermediateresult. To begin, the DSTN module accesses the translated data (from thescratchpad memory or from the intermediate result memory and decodes it)and partitions it into a plurality of partitions in accordance with theDST allocation information. For each partition of the third intermediateresult, the DSTN identifies a set of its DT execution modules 90 toperform task 1_4 in accordance with the DST allocation information(e.g., DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1 are allocated totranslate back partitions R1-3_1 through R1-3_4 and DT execution modules1_2, 2_2, 6_1, 7_1, and 7_2 are allocated to translate back partitionsR1-3_5 through R1-3 _(—) z). For the partitions, the allocated set of DTexecution modules executes task 1_4 to produce partial results 102(e.g., 1^(st) through “zth”) of re-translated data.

As indicated in the DST allocation information of FIG. 32, DST executionunit 3 is assigned to process the first through “zth” partial results oftask 1_4 to produce the fourth intermediate result (R1-4), which isretranslated data. The processing module of DST execution 3 is engagedto aggregate the first through “zth” partial results of retranslateddata to produce the fourth intermediate result. The processing modulestores the fourth intermediate result as non-DS error encoded data inthe scratchpad memory or in another section of memory of DST executionunit 3.

DST execution unit 3 engages its DST client module to slice groupingbased DS error encode the fourth intermediate result (e.g., retranslateddata). To begin the encoding, the DST client module partitions thefourth intermediate result (R1-4) into a plurality of partitions (e.g.,R1-4_1 through R1-4 _(—) z). For each partition of the fourthintermediate result, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 3-7 per the DSTallocation information).

In FIG. 36, a distributed storage and task network (DSTN) module isperforming task 1_5 (e.g., compare) on data 92 and retranslated data ofFIG. 35. To begin, the DSTN module accesses the data 92 and partitionsit into a plurality of partitions in accordance with the DST allocationinformation or it may use the data partitions of task 1_1 if thepartitioning is the same. The DSTN module also accesses the retranslateddata from the scratchpad memory, or from the intermediate result memoryand decodes it, and partitions it into a plurality of partitions inaccordance with the DST allocation information. The number of partitionsof the retranslated data corresponds to the number of partitions of thedata.

For each pair of partitions (e.g., data partition 1 and retranslateddata partition 1), the DSTN identifies a set of its DT execution modules90 to perform task 1_5 in accordance with the DST allocation information(e.g., DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1). For each pairof partitions, the allocated set of DT execution modules executes task1_5 to produce partial results 102 (e.g., 1^(st) through “zth”) of alist of incorrectly translated words and/or phrases.

As indicated in the DST allocation information of FIG. 32, DST executionunit 1 is assigned to process the first through “zth” partial results oftask 1_5 to produce the fifth intermediate result (R1-5), which is thelist of incorrectly translated words and/or phrases. In particular, theprocessing module of DST execution 1 is engaged to aggregate the firstthrough “zth” partial results of the list of incorrectly translatedwords and/or phrases to produce the fifth intermediate result. Theprocessing module stores the fifth intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 1.

DST execution unit 1 engages its DST client module to slice groupingbased DS error encode the fifth intermediate result. To begin theencoding, the DST client module partitions the fifth intermediate result(R1-5) into a plurality of partitions (e.g., R1-5_1 through R1-5 _(—)z). For each partition of the fifth intermediate result, the DST clientmodule uses the DS error encoding parameters of the data (e.g., DSparameters of data 2, which includes 3/5 decode threshold/pillar widthratio) to produce slice groupings. The slice groupings are stored in theintermediate result memory (e.g., allocated memory in the memories ofDST execution units 1-5 per the DST allocation information).

As is further shown in FIG. 36, the DSTN module is performing task 1_6(e.g., translation errors due to non-words) on the list of incorrectlytranslated words and/or phrases (e.g., the fifth intermediate resultR1-5) and the list of non-words (e.g., the first intermediate resultR1-1). To begin, the DSTN module accesses the lists and partitions theminto a corresponding number of partitions.

For each pair of partitions (e.g., partition R1-1_1 and partitionR1-5_1), the DSTN identifies a set of its DT execution modules 90 toperform task 1_6 in accordance with the DST allocation information(e.g., DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1). For each pairof partitions, the allocated set of DT execution modules executes task1_6 to produce partial results 102 (e.g., 1^(st) through “zth”) of alist of incorrectly translated words and/or phrases due to non-words.

As indicated in the DST allocation information of FIG. 32, DST executionunit 2 is assigned to process the first through “zth” partial results oftask 1_6 to produce the sixth intermediate result (R1-6), which is thelist of incorrectly translated words and/or phrases due to non-words. Inparticular, the processing module of DST execution 2 is engaged toaggregate the first through “zth” partial results of the list ofincorrectly translated words and/or phrases due to non-words to producethe sixth intermediate result. The processing module stores the sixthintermediate result as non-DS error encoded data in the scratchpadmemory or in another section of memory of DST execution unit 2.

DST execution unit 2 engages its DST client module to slice groupingbased DS error encode the sixth intermediate result. To begin theencoding, the DST client module partitions the sixth intermediate result(R1-6) into a plurality of partitions (e.g., R1-6_1 through R1-6 _(—)z). For each partition of the sixth intermediate result, the DST clientmodule uses the DS error encoding parameters of the data (e.g., DSparameters of data 2, which includes 3/5 decode threshold/pillar widthratio) to produce slice groupings. The slice groupings are stored in theintermediate result memory (e.g., allocated memory in the memories ofDST execution units 2-6 per the DST allocation information).

As is still further shown in FIG. 36, the DSTN module is performing task1_7 (e.g., correctly translated words and/or phrases) on the list ofincorrectly translated words and/or phrases (e.g., the fifthintermediate result R1-5) and the list of unique words (e.g., the secondintermediate result R1-2). To begin, the DSTN module accesses the listsand partitions them into a corresponding number of partitions.

For each pair of partitions (e.g., partition R1-2_1 and partitionR1-5_1), the DSTN identifies a set of its DT execution modules 90 toperform task 1_7 in accordance with the DST allocation information(e.g., DT execution modules 1_2, 2_2, 3_2, 4_2, and 5_2). For each pairof partitions, the allocated set of DT execution modules executes task1_7 to produce partial results 102 (e.g., 1^(st) through “zth”) of alist of correctly translated words and/or phrases.

As indicated in the DST allocation information of FIG. 32, DST executionunit 3 is assigned to process the first through “zth” partial results oftask 1_7 to produce the seventh intermediate result (R1-7), which is thelist of correctly translated words and/or phrases. In particular, theprocessing module of DST execution 3 is engaged to aggregate the firstthrough “zth” partial results of the list of correctly translated wordsand/or phrases to produce the seventh intermediate result. Theprocessing module stores the seventh intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 3.

DST execution unit 3 engages its DST client module to slice groupingbased DS error encode the seventh intermediate result. To begin theencoding, the DST client module partitions the seventh intermediateresult (R1-7) into a plurality of partitions (e.g., R1-7_1 through R1-7_(—) z). For each partition of the seventh intermediate result, the DSTclient module uses the DS error encoding parameters of the data (e.g.,DS parameters of data 2, which includes 3/5 decode threshold/pillarwidth ratio) to produce slice groupings. The slice groupings are storedin the intermediate result memory (e.g., allocated memory in thememories of DST execution units 3-7 per the DST allocation information).

In FIG. 37, the distributed storage and task network (DSTN) module isperforming task 2 (e.g., find specific words and/or phrases) on the data92. To begin, the DSTN module accesses the data and partitions it into aplurality of partitions 1-z in accordance with the DST allocationinformation or it may use the data partitions of task 1_1 if thepartitioning is the same. For each data partition, the DSTN identifies aset of its DT execution modules 90 to perform task 2 in accordance withthe DST allocation information. From data partition to data partition,the set of DT execution modules may be the same, different, or acombination thereof. For the data partitions, the allocated set of DTexecution modules executes task 2 to produce partial results 102 (e.g.,1^(st) through “zth”) of specific words and/or phrases found in the datapartitions.

As indicated in the DST allocation information of FIG. 32, DST executionunit 7 is assigned to process the first through “zth” partial results oftask 2 to produce task 2 intermediate result (R2), which is a list ofspecific words and/or phrases found in the data. The processing moduleof DST execution 7 is engaged to aggregate the first through “zth”partial results of specific words and/or phrases to produce the task 2intermediate result. The processing module stores the task 2intermediate result as non-DS error encoded data in the scratchpadmemory or in another section of memory of DST execution unit 7.

DST execution unit 7 engages its DST client module to slice groupingbased DS error encode the task 2 intermediate result. To begin theencoding, the DST client module determines whether the list of specificwords and/or phrases is of a sufficient size to partition (e.g., greaterthan a Terabyte). If yes, it partitions the task 2 intermediate result(R2) into a plurality of partitions (e.g., R2_1 through R2 _(—) m). Ifthe task 2 intermediate result is not of sufficient size to partition,it is not partitioned.

For each partition of the task 2 intermediate result, or for the task 2intermediate results, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-4, and 7).

In FIG. 38, the distributed storage and task network (DSTN) module isperforming task 3 (e.g., find specific translated words and/or phrases)on the translated data (R1-3). To begin, the DSTN module accesses thetranslated data (from the scratchpad memory or from the intermediateresult memory and decodes it) and partitions it into a plurality ofpartitions in accordance with the DST allocation information. For eachpartition, the DSTN identifies a set of its DT execution modules toperform task 3 in accordance with the DST allocation information. Frompartition to partition, the set of DT execution modules may be the same,different, or a combination thereof. For the partitions, the allocatedset of DT execution modules 90 executes task 3 to produce partialresults 102 (e.g., 1^(st) through “zth”) of specific translated wordsand/or phrases found in the data partitions.

As indicated in the DST allocation information of FIG. 32, DST executionunit 5 is assigned to process the first through “zth” partial results oftask 3 to produce task 3 intermediate result (R3), which is a list ofspecific translated words and/or phrases found in the translated data.In particular, the processing module of DST execution 5 is engaged toaggregate the first through “zth” partial results of specific translatedwords and/or phrases to produce the task 3 intermediate result. Theprocessing module stores the task 3 intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 7.

DST execution unit 5 engages its DST client module to slice groupingbased DS error encode the task 3 intermediate result. To begin theencoding, the DST client module determines whether the list of specifictranslated words and/or phrases is of a sufficient size to partition(e.g., greater than a Terabyte). If yes, it partitions the task 3intermediate result (R3) into a plurality of partitions (e.g., R3_1through R3 _(—) m). If the task 3 intermediate result is not ofsufficient size to partition, it is not partitioned.

For each partition of the task 3 intermediate result, or for the task 3intermediate results, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-4, 5, and 7).

FIG. 39 is a diagram of an example of combining result information intofinal results 104 for the example of FIG. 30. In this example, theresult information includes the list of specific words and/or phrasesfound in the data (task 2 intermediate result), the list of specifictranslated words and/or phrases found in the data (task 3 intermediateresult), the list of non-words found in the data (task 1 firstintermediate result R1-1), the list of unique words found in the data(task 1 second intermediate result R1-2), the list of translation errorsdue to non-words (task 1 sixth intermediate result R1-6), and the listof correctly translated words and/or phrases (task 1 seventhintermediate result R1-7). The task distribution module provides theresult information to the requesting DST client module as the results104.

FIG. 40A is a schematic block diagram of an embodiment of a dispersedstorage network that includes the distributed storage and task (DST)client module 34 of FIG. 1 and a set of DST execution units 1-n. EachDST execution unit may be implemented with the DST execution unit 36 ofFIG. 1. Hereafter, each DST execution unit may be referred tointerchangeably as a storage unit of a set of storage units.

In an embodiment, a dispersed storage and task (DST) processing unit 16of FIG. 1 includes the DST client module 34, when operable within acomputing device, causes the computing device to perform a series ofsteps. In an example of operation of the steps, the DST client module 34receives a storage request 400 to store a low retention priority dataobject in the DSN (e.g., receives a write facilitating request). Thestorage request 400 may include one or more of the low retentionpriority data object, a retention priority level associated with the lowretention priority data object, a data name, a requesting entityidentifier, a data owner identifier, and a storage indicator. The lowretention priority data object may include any data that requirestemporary storage (e.g., scratchpad data). Having received the storagerequest 400, DST client module 34 sends a set of low retention prioritywrite requests (e.g., write and retain slice requests 1-n) to storageunits of the DSN. As a specific example, the DST client module 34generates each low retention priority write request of the set of lowretention priority write requests to include a low retention priorityquery. For instance, the DST client module 34 generates the lowretention priority query to include queries regarding different levelsof low retention priority data.

As another specific example of sending the set of low retention prioritywrite requests, the DST client module 34 includes a set of encoded dataslices within the set of low retention priority write requests whensending the set of low retention priority write requests, where a datasegment of a low retention priority data object is dispersed storageerror encoded to produce the set of encoded data slices.

For each storage unit of the storage units that receives a low retentionpriority write request of the set of low retention priority writerequests, the storage unit determines a low retention priority response(e.g., storage utilization information) regarding availability forstoring low retention priority data based on current storage of lowpriority data objects and available memory for storing the low retentionpriority data. As a specific example, each storage unit determineswhether there is available memory for storing the low retention prioritydata. For instance, the storage unit determines total available memorywithin the storage unit, determines a level of storage of higherpriority data objects, and determines whether there is available memoryfor storing the low retention priority data based on the total availablememory and the level of storage of the higher priority data objects.

When there is not available memory for storing the low retentionpriority data, the storage unit compares retention priority of anencoded data slice of another low retention priority data object of thecurrent storage of low priority data objects with a retention priorityof an encoded data slice of the set of encoded data slices. When theretention priority of the encoded data slice of the set of encoded dataslices compares favorably to the retention priority of the encoded dataslice of the other low retention priority data object (e.g., priority ofencoded data slice greater than priority of other low retention prioritydata object), the storage unit overwrites the encoded data slice of theother low retention priority data object with the encoded data slice ofthe set of encoded data slices and generates a write response toindicate storage of the encoded data slice.

Having determined the low retention priority response, the storage unitsends the low retention priority response to the DST client module 34(e.g., the DST execution units issue storage utilization information1-n). As a specific example, the storage unit sends the write response.

When a threshold number (e.g., a write threshold number) of favorablelow retention priority responses have been received, the DST clientmodule 34 facilitates storage of the low retention priority data object.As a specific example, the DST client module 34 sends a set of writecommit requests to each storage unit sending the write response. Asanother specific example, when generating the low retention priorityquery to include the queries regarding the different levels of lowretention priority data, for a given low retention priority level of thelow retention priority data object to be stored, the DST client module34 determines whether the threshold number of favorable low retentionpriority responses have been received. When the threshold number offavorable low retention priority responses have been received for thegiven low retention priority level, the DST client module 34 facilitatesthe storage of the low retention priority data object.

As yet another specific example of facilitating the storage of the lowretention priority data object, the DST client module 34 sends, forstorage, the set of encoded data slices to the storage units providingthe favorable low retention priority response, where the data segment ofthe low retention priority data object is dispersed storage errorencoded to produce the set of encoded data slices. For each storage unitreceiving an encoded data slice of the set of encoded data slices, thestorage unit determines whether there is low retention priority memorycurrently available.

When the low retention priority memory is not currently available, thestorage unit compares retention priority of an encoded data slice ofanother low retention priority data object of the current storage of lowpriority data objects with a retention priority of an encoded data sliceof the set of encoded data slices. When the retention priority of theencoded data slice of the set of encoded data slices compares favorablyto the retention priority of the encoded data slice of the other lowretention priority data object, the storage unit overwrites the encodeddata slice of the other low retention priority data object with theencoded data slice of the set of encoded data slices and sends a writeresponse.

The method described above in conjunction with a DST processing unit 16can alternatively be performed by other modules of a dispersed storagenetwork, of a distributed storage and task network or by other devices.In addition, at least one memory section that stores operationalinstructions that can, when executed by one or more processing modulesof one or more computing devices of a dispersed storage network (DSN),cause the one or more computing devices to perform any or all of themethod steps described above.

In another example of operation, the DST client module 34 receivesstorage utilization information 1-n from the set of DST execution units1-n. The set of DST execution units 1-n issues the storage utilizationinformation 1-n based on one or more of receiving a request, inaccordance with a schedule, and when detecting a storage utilizationchange.

The storage utilization information includes one or more of a totalamount of storage capacity, a total amount of storage capacity utilized,a total amount of remaining storage capacity, and storage utilization byretention priority level. The retention priority level indicates underwhich conditions an associated encoded data slice is to be retained ornot retained by an associated DST execution unit storing the encodeddata slice. The retention priority level includes any number of levels.For example, the associated encoded data slice is never to be deleted bythe DST execution unit when the retention priority level indicatesretain indefinitely. As another example, a first encoded data sliceassociated with a first retention priority level shall not be deletedbefore a second encoded data slice associated with a second retentionpriority level when the first retention priority level indicates agreater requirement for retention than the second priority level.

The DST client module 34 receives the storage request 400, where thedata storage request 400 may further include one or more of a requesteddata retention priority level, data for storage, a data identifier, adata type indicator, a data size indicator, a data owner identifier(ID), a vault ID, and a storage request type (e.g., write, read). TheDST client module 34 encodes the data of a write storage request using adispersed storage error coding function into sets of encoded dataslices. For each set of encoded data slices, the DST client module 34determines an associated retention priority level for at least a writethreshold number of encoded data slices of the set of encoded dataslices. The determining may be based on one or more of the receivedrequested data retention priority level, the data type indicator, thedata identifier, the data size indicator, the data owner ID, and thevault ID. As a specific example, the DST client module 34 determines theretention priority level to be indefinitely retain the write thresholdnumber of encoded data slices when the requested data retention prioritylevel includes indefinitely retain and the data owner ID is included ina high priority data owner list. As another specific example, the DSTclient module 34 determines the retention priority level to be a lowestretention level when the data ID matches a list of data IDs ofredundantly stored data (e.g., other copies exist).

When at least a write threshold number of DST execution units reportstorage utilization information that indicates that each DST executionunit has sufficient available storage capacity for storage of encodeddata slices of the write threshold number of encoded data slices, theDST client module generates a write threshold number of write andretrain slice requests of a set of write and retain slice requests 1-n.The DST client module 34 determines whether the DST execution unit hassufficient available storage capacity by comparing an available storagecapacity utilization of the storage utilization information to a size ofa corresponding encoded data slice. The write and retain requestincludes one or more corresponding encoded data slices (e.g., for one ormore sets) and the determined retention priority level. The DST clientmodule 34 sends the write threshold number of write and retain slicerequests to a corresponding write threshold number of DST executionunits of the set of DST execution units.

The DST execution unit receives a corresponding write and retain slicerequest. The DST execution unit determines whether sufficient availablestorage capacity exists to store each encoded data slice of the request.The sufficient available storage capacity includes one of sufficientavailable unused storage capacity or sufficient available reclaimablestorage capacity (e.g., by deleting slices of a lower retention prioritylevel). The DST execution unit indicates that the sufficient availableunused storage capacity exists when an amount of unused storage capacityis greater than required storage capacity (e.g. based on size ofreceived slices). The DST execution unit indicates that the sufficientavailable reclaimable storage capacity exists when the sufficientavailable unused storage capacity does not exist and an amount of thesufficient available reclaimable storage capacity associated withstorage of slices of the lower retention priority level than theretention priority level is greater than the required storage capacity.

When the DST execution unit indicates the sufficient availablereclaimable storage capacity, the DST execution unit selects the slicesof the lower retention priority level than the retention priority levelto produce selected slices for deletion. Next, the DST execution unitdeletes the selected slices for deletion and stores each encoded dataslice of the request. The DST execution unit indicates that sufficientavailable storage capacity is not available when the sufficientavailable unused storage capacity does not exist and the sufficientavailable reclaimable storage capacity does not exist. As a specificexample, the DST execution unit indicates that sufficient availablestorage capacity is not available when the sufficient available unusedstorage capacity does not exist and all stored slices are associatedwith higher retention priority levels than the retention priority levelof each encoded data slice of the request. When the sufficient availablestorage capacity is not available, the DST execution unit issues arejection response to the DST client module 34.

FIG. 40B is a flowchart illustrating an example of prioritizing dataretention. The method includes step 402 where a processing module (e.g.,of one or more processing modules of a dispersed storage network (DSN))sends a set of low retention priority write requests to storage units ofthe DSN. Each low retention priority write request of the set of lowretention priority write requests includes a low retention priorityquery, where generating the low retention priority query may includequeries regarding different levels of low retention priority data.Alternatively, the processing module includes a set of encoded dataslices within the set of low retention priority write requests whensending the set of low retention priority write requests, where a datasegment of a low retention priority data object is dispersed storageerror encoded to produce the set of encoded data slices.

For each storage unit of the storage units that receives a low retentionpriority write request of the set of low retention priority writerequests, the method continues at step 404 where the storage unitdetermines a low retention priority response regarding availability forstoring low retention priority data based on current storage of lowpriority data objects and available memory for storing the low retentionpriority data. As a specific example, the processing module determineswhether there is available memory for storing the low retention prioritydata. For instance, the processing module determines total availablememory within the storage unit, determines a level of storage of higherpriority data objects, and determines whether there is available memoryfor storing the low retention priority data based on the total availablememory and the level of storage the higher priority data objects.

When there is not available memory for storing the low retentionpriority data, the processing module compares retention priority of anencoded data slice of another low retention priority data object of thecurrent storage of low priority data objects with a retention priorityof an encoded data slice of the set of encoded data slices. When theretention priority of the encoded data slice of the set of encoded dataslices compares favorably to the retention priority of the encoded dataslice of the other low retention priority data object, the processingmodule overwrites the encoded data slice of the other low retentionpriority data object with the encoded data slice of the set of encodeddata slices and generates a write response.

The method continues at step 406 where the processing module sends thelow retention priority response. As a specific example, the processingmodule sends the write response. When a threshold number (e.g., a writethreshold number) of favorable low retention priority responses havebeen received, the method continues at step 408 where the processingmodule facilitates storage of a low retention priority data object. As aspecific example, the processing module sends a set of write commitrequests to each storage unit sending the write response.

As another specific example, when generating the low retention priorityquery to include queries regarding different levels of low retentionpriority data, for a given low retention priority level of the lowretention priority data object to be stored, the processing moduledetermines whether the threshold number of favorable low retentionpriority responses have been received. When the threshold number offavorable low retention priority responses have been received for thegiven low retention priority level, the processing module facilitatesthe storage of the low retention priority data object.

As yet another example of the facilitating of the storage of the lowretention priority data object, the processing module sends, forstorage, a set of encoded data slices to the storage units providing thefavorable low retention priority response, where the data segment of thelow retention priority data object is dispersed storage error encoded toproduce the set of encoded data slices. For each storage unit receivingan encoded data slice of the set of encoded data slices, the processingmodule determines whether there is low retention priority memorycurrently available.

When the low retention priority memory is not currently available, theprocessing module compares retention priority of an encoded data sliceof another low retention priority data object of the current storage oflow priority data objects with a retention priority of an encoded dataslice of the set of encoded data slices. When the retention priority ofthe encoded data slice of the set of encoded data slices comparesfavorably to the retention priority of the encoded data slice of theother low retention priority data object, the processing moduleoverwrites the encoded data slice of the other low retention prioritydata object with the encoded data slice of the set of encoded dataslices and sends a write response.

FIG. 41A is a schematic block diagram of another embodiment of adispersed storage network (DSN) that includes the distributed storageand task (DST) processing unit 16 of FIG. 1 and the distributed storageand task network (DSTN) managing unit 18 of FIG. 1. The DSN functions toprovision a vault. In an example of operation, the DSTN managing unit 18generates a plurality of vault templates 430 based on one or more of amanager input, a previous vault, DSN network configuration information,DSN capabilities, a vault list, and an expected vault list. As aspecific example, the DSTN managing unit 18 updates a previous vaulttemplate based on the DSN network configuration information to produce afirst vault template.

Each vault template 430 includes a plurality of fields, where each fieldincludes one or more entries. The plurality of fields includes atemplate name field 428 that includes a name entry for the template, awidth field 432 that includes a width entry (e.g., dispersed storagepillar width parameter), a decode threshold field 434 that includes adecode threshold entry (e.g., dispersed storage decode thresholdparameter), a storage pools field 436 that includes entries ofidentifiers of storage units of one or more storage pools, a storagequotas field 438 that includes entries of storage quota maximumsassociated with one or more users of the vault, a codecs field 440 thatincludes one or more entries of codecs utilized in dispersed storageerror coding (e.g., a compression algorithm identifier, a encodingalgorithm identifier, a integrity check algorithm identifier, etc.), aDST processing units field 442 that includes entries of identifiers ofone or more DST processing units, and initial vault access control list(ACL) field 444 that includes one or more entries of access controlinformation (e.g., permissions), and another vault information field 446that includes one or more other vault information entries (e.g., anyother common vault information required to support operation of thevault).

The operational example continues where the DSTN managing unit 18receives a vault provisioning request 420 from a device (e.g., the DSTprocessing unit 16) of the DSN, where the request 420 includes a vaultname 426 (e.g., a new vault name) and a template name 428. The DSTNmanaging unit 18 verifies that the device is authorized to requestprovisioning of a vault (e.g., verifying with an access control list).When verified, the DSTN managing unit 18 obtains a vault template 430that corresponds to the template name 428 of the vault provisioningrequest 420 (e.g., match template name entry of the vault template tothe template name received in the vault provisioning request).

The DSTN managing unit 18 generates a new vault using the vault templateby signing the vault name 426 of the vault provisioning request 420 andupdating an access control list field 444 in accordance with the initialvault access control list and identifier of the device. As a specificexample, the DSTN managing unit 18 enables the DST processing unit 16 tofully utilize and modify the vault as indicated in the ACL of the vault.The DSTN managing unit 18 activates the new vault. As a specificexample, the DSTN managing unit 18 stores the new vault in a registryand publishes the registry to devices of the DSN as a registrypublication 424. The DSTN managing unit 18 issues a vault provisioningresponse 422 to the device, where the response includes an indicatorthat the new vault of the vault name has been activated.

FIG. 41B is a flowchart illustrating an example of activating a newdispersed storage network vault. The method continues at step 448 wherea processing module (e.g., of a distributed storage and task network(DSTN) managing unit) generates a plurality of vault templates. Themethod continues at step 450 where the processing module receives avault provisioning request from a device of a dispersed storage network(DSN), where the vault provisioning request includes a vault name and avault template name. The method continues at step 452 where theprocessing module verifies that the device is authorized to request avault provisioning. As a specific example, the processing moduleaccesses a current access control list of current registry informationto determine whether the device has been assigned rights to request thevault provisioning.

When favorably authorized, the method continues at step 454 where theprocessing module retrieves a vault template of the plurality of alltemplates, where the vault template is associated with the vaulttemplate name. The method continues at step 456 where the processingmodule generates a new vault using the vault template to includeassigning the vault name to the new vault. The generating furtherincludes updating an access control list field of the new vault inaccordance with the initial vault access control list and an identifierof the device. The method continues at step 458 where the processingmodule activates the new vault. The method continues at step 460 wherethe processing module issues a vault provisioning response to thedevice, where the response includes one or more of the vault name, anindicator that the new vault has been activated, and a plurality ofentries of the new vault.

FIG. 42A is a schematic block diagram of another embodiment of adistributed storage and task (DST) execution unit 36 of FIG. 11. The DSTexecution unit 36 includes a variety of devices including the interface169, a plurality of memories 88, the controller 86, a plurality ofdistributed task (DT) execution modules 90, and a plurality of DSTclient modules 34 of FIG. 11. The DST execution unit 36 further includesa power distribution module 462 and an anomaly detection module 464. TheDST execution unit 36 functions to detect an anomaly associated withoperation and control of the variety of devices as the variety ofdevices process partial task requests 98 to provide one or more ofresults 104, partial results 102, sub-slice groupings 170, andsub-partial task 172; store slices 96; and recover slices 100. Thecontroller 86 controls the variety of devices. For example, thecontroller 86 issues a memory control 174 to control the plurality ofmemories 88. As another example, the controller 86 issues a task control480 to control the plurality of DT execution modules 90. As yet anotherexample, the controller 86 issues a DST control 482 to control theplurality of DST client modules 34.

The controller 86 monitors the operation of the variety devices andgenerates activity information 476 which includes, for each device ofthe DST execution unit 36, an identifier of the device, and an activityindicator by time. The activity information 476 further includesactivity of the DST execution unit 36 (e.g., processing a partial task98, storing a slice 96, retrieving a slice 100, etc.). As a specificexample, the controller 86 indicates that a first memory 88 performs aseries of write operations in response to a slice access requestreceived by the DST execution unit 36 during a first timeframe and thefirst memory 88 is idle during a second timeframe. As another specificexample, the controller 86 indicates that a first DT execution module 90processed a partial task in response to a partial task execution request98 during the first timeframe and was idle during the second timeframe.As yet another specific example, the controller 86 indicates that asecond DST client module 34 and a third DST client module 34 where bothidle during the first and second timeframes.

The power distribution module 462 receives input power 466, via theinterface 169, and provides power to devices of the DST execution unit36. As a specific example, the power distribution module 462 providesmemory power 468 to the plurality of memories 88, DT power 470 to theplurality of DT execution modules 90, and DST power 472 to the pluralityof DST client modules 34. The power distribution module 462 determinespower utilization (e.g., over time as associated with a representationof time) of each device of each of the pluralities of memories 88, DTexecution modules 90, and the DST client modules 34. As a specificexample, the power distribution module 462 determines power utilizationof the first memory 88 to be 100 milliamps (mA) during the firsttimeframe and 25 mA during the second timeframe. As another specificexample, the power distribution module 462 determines power utilizationof the first DT execution module 90 of 75 mA during the first timeframeand 10 mA during the second timeframe. As yet another specific example,the power distribution module 462 determines power utilization of thesecond DST client module 34 of 110 mA during the first and secondtimeframes and power utilization of the third DST client module 34 of 5mA during the first and second timeframes.

The power distribution module 462 generates power usage information 474based on the determined power utilization. The power usage information474 includes, for each device of the DST execution unit 36, anidentifier of the device, and a power utilization level of the device bytime. The power distribution module 462 sends the power usageinformation to the anomaly detection module 464.

In an example of detecting the anomaly, the anomaly detection module 464receives the activity information 476 and the power usage information474. The anomaly detection module 464 stores the activity information476 and the power usage information 474 to include common timereferences. The anomaly detection module 464 analyzes the activityinformation 476 and the power usage information 474 by common timeframes of the common time references to produce trend information. Theanomaly detection module 464 stores the trend information, whichincludes a correlation of the activity information 476 and the powerusage information 474 over time. For example, the trend informationindicates that the first memory device 88 utilizes 100 mA to perform theseries of write operations during the first timeframe and utilizes 25 mAwhen idle during the second timeframe. As another example, the trendinformation indicates that the first DT execution module 90 utilizes 75mA to process a partial task in the first timeframe and utilizes 10 mAwhen idle during the second timeframe. As yet another example, the trendinformation indicates that the second DST client module 34 utilizes 110mA when idle and the third DST client module 34 utilizes 5 mA when idle.

The anomaly detection module 464 detects the anomaly based on the trendinformation to include comparing recent trend information to historicallong-term trend information. In particular, the anomaly may be detectedbased on an indication that too much power or too little power is beingutilized for a current activity of the activity information. As aspecific example, the anomaly detection module detects the anomaly asthe second DST client module utilizing more power (e.g., more than apower threshold level amount) than the third DST client module 34 whenboth are idle. When detecting the anomaly, the anomaly detection moduleissues one or more alerts 478 based on the anomaly. For example, theanomaly detection module 464 issues, via the interface 169, an alert 478that indicates that the third DST client module 34 is utilizing too muchpower. As another example, the anomaly detection module 464 issuesanother alert 478 that indicates that a tenth DT execution module 90 isutilizing too little power when the tenth DT execution module 90utilizes less power (e.g., by more than another power threshold levelamount) than other DT execution modules 90 for a similar activity.

FIG. 42B is a flowchart illustrating an example of detecting aprocessing activity anomaly. The method continues at step 490 where aprocessing module (e.g., of an anomaly detection module associated witha distributed storage and task (DST) execution unit) receives powerusage information for a plurality of devices with regards to processingactivity. The receiving includes one or more of issuing a query,receiving a query response, and receiving an error message. The methodcontinues at step 492 where the processing module receives activityinformation for the plurality of devices with regards to the processingactivity. The receiving includes one or more of issuing a query,receiving a query response, and receiving an error message. The methodcontinues at step 494 where the processing module stores time stampedpower usage and activity information to produce a historical record. Asa specific example, the processing module obtains a current timestampand generates the historical record to include the current timestamp andat least some of the power usage and activity information.

The method continues at step 496 where the processing module analyzeshistorical records to produce trend information. As a specific example,the processing module correlates activity with power usage to producethe trend information (e.g., by types of activities and by power usageby device). The method continues at step 498 where the processing moduledetects an anomaly of a portion of the processing activity based on thetrend information. For example, the processing module, for a currentactivity, analyzes current power usage for one or more devices andidentifies at least one device associated with power usage by activitythat compares unfavorably to the trend information (e.g., powerconsumption too high, power consumption too low).

The method continues at step 500 where the processing module issues analert based on the detected anomaly. The issuing includes generating thealert to include one or more of a device identifier of the at least onedevice, a current power usage level of the device, a current activity ofthe device, and an expected current power usage based on the trendinformation. The method continues at step 502 where the processingmodule determines a remedy for the detected anomaly. The determiningincludes one or more of identifying another device of the pluralitydevices to perform a task of the at least one device (e.g., selectinganother device of the DST execution unit) and identifying anotherplurality devices where at least one device of the other plurality ofdevices can perform the task of the at least one device (e.g., selectinganother DST execution unit). The method continues at step 504 where theprocessing module initiates execution of the remedy. As a specificexample, the processing module extracts task processing information fromthe at least one device, sends the task processing information to theidentified other device, and instructs the at least one device to ceaseprocessing of the task.

FIG. 43A is a schematic block diagram of another embodiment of adispersed storage network (DSN) that includes the distributed storageand task network (DSTN) managing unit 18 of FIG. 1 and a set of DSTexecution units 1-n. Each DST execution unit may be implementedutilizing the DST execution unit 36 of FIG. 1. In an example ofoperation, the DSTN managing unit 18 obtains status information from theset of DST execution units 1-n as status information 1-n. The statusinformation includes one or more of an availability indicator, an activeindicator, a required for a rebuilding indicator, a requiring rebuildingindicator, identifiers of DST execution units required for rebuilding,the number of pending data access requests, a number of pendingprocessing requests, and power utilization level information. Theobtaining includes at least one of issuing a query, receiving a queryresponse, receiving an error message, receiving an activation chainstatus response, and accessing a historical record.

The DSTN managing unit 18 selects a DST execution unit associated withan inactive status for reactivation in accordance with a rotation schemeand based on the status information, where a number of remaining DSTexecution units of the set of DST execution units is greater than orequal to a decode threshold number. The rotation scheme includes atleast one of a round-robin scheme, an equal amount of downtime, and anequal amount of downtime. The selecting may be based on one or more of apower utilization level, a desired power utilization level, a number ofdesired active units, a desired reliability level, a desiredavailability level, and DST execution unit capabilities.

With the DST execution unit for reactivation selected, the DSTN managingunit 18 issues an activation status change request to the selected DSTexecution unit. The activation status change request includes one ormore of a DST execution unit ID, a requested status (e.g., not active,active), and a status transition approach (e.g., immediately, at ascheduled future timeframe, when no current or pending data accessrequest exists, when no current or pending rebuilding activity exists).As a specific example, the activation status change request includes arequest to reactivate and a transition approach for immediate transition(e.g., alternatively for a scheduled transition in accordance with atleast one of a transition schedule and a request).

The DSTN managing unit 18 receives a favorable activation status changeresponse from the selected DST execution unit for reactivation. Theactivation status change response includes one or more of the DSTexecution unit identifier, the requested status, the actual status, anumber of current or pending data access request, a number of current orpending rebuilding task, and an estimated time to status transition whennot immediate. As a specific example, the activation status changeresponse includes an indicator that the DST execution unit is nowactive.

With the DST execution units selected for reactivation now active, theDSTN managing unit 18 selects another DST execution unit associated withan active status for deactivation in accordance with the rotation schemeand based on the status information, where a number of remaining DSTexecution units of the set of DST execution units is greater than orequal to a decode threshold number. The selecting may be based on one ormore of a power utilization level, a desired power utilization level, anumber of desired active units, a desired reliability level, a desiredavailability level, DST execution unit capabilities, and identifying aDST execution unit associated with a number of pending tasks that isless than a low pending tasks threshold level (e.g., few or no pendingpartial task processing tasks, few or no pending data access tasks).

With the other DST execution units selected for deactivation, the DSTNmanaging unit 18 determines a transition approach for the other DSTexecution unit based on the status information (e.g., immediately,scheduled, after pending tasks are executed). As a specific example, theDSTN managing unit 18 determines the transition approach to be theimmediate approach when a priority of estimated power savings is greaterthan all other priorities. As another specific example, the DSTNmanaging unit 18 determines the transition approach to be after thepending tasks are executed when the pending tasks include criticalrebuilding tasks and the critical rebuilding tasks are associated with apriority that is greater than all other priorities. With the transitionapproach determined, the DSTN managing unit 18 issues and activationstatus change request to the other DST execution unit, where theactivation status change request includes the transition approach and arequest to deactivate. The method to change activation status isdiscussed in greater detail with reference to FIG. 43B.

From time to time, one or more of the DST execution units rebuildsencoded data slices associated with slice errors. The rebuildingincludes scanning for errors and remedying the errors. The DST executionunits share rebuilding information 510. The rebuilding information 510includes one or more of a list slice request, a list of slice response,a read slice request, a read slice response, a partial slice request,and the partial slice response. The scanning for errors includes a DSTexecution unit associated with an active status issuing list slicerequests other act of DST execution units and receiving list sliceresponses for comparison to identify slice errors. The remedyingincludes an active DST execution unit obtaining at least a decodethreshold number of representations of encoded data slices of a set ofencoded data slices where at least one encoded data slice is associatedwith a slice error. The obtaining includes issuing one or more of readslice requests and read partial slice requests to active DST executionunits and receiving one or more of read slice responses and read partialslice responses. The obtaining further includes waiting for required DSTexecution units to become active prior to sending of the one or more ofthe read slice requests and the read partial slice requests. The methodof rebuilding is discussed in greater detail with reference to FIG. 44.

FIG. 43B is a flowchart illustrating an example of selecting activestorage units. The method continues at step 512 where a processingmodule (e.g., of a distributed storage and task network (DSTN) managingunit) obtains status information for a set of storage units. The methodcontinues at step 514 where the processing module selects a storage unitassociated with an inactive status for reactivation in accordance with arotation scheme and based on the status information. As a specificexample, the processing module selects a next storage unit of a storageunit rotation list, where the storage unit is associated with anavailable and inactive status. The method continues at step 516 wherethe processing module issues and activation status change request to theselected storage unit to reactivate the storage unit. The methodcontinues at step 518 where the processing module receives an activationstatus change response from the selected storage unit indicating thatthe storage unit has been reactivated.

When the activation status change response includes a favorableactivation status change indicator (e.g., indicating that the selectedstorage unit has been reactivated), the method continues at step 520where the processing module selects another storage unit associated withan active status for deactivation in accordance with the rotation schemeand based on the status information. As a specific example, theprocessing module selects the other storage unit where the other storageunit is associated with no pending storage or rebuilding tasks. Themethod continues at step 522 where the processing module determines atransition approach for the selected other storage unit based on thestatus information. As a specific example, the processing moduledetermines the transition approach to include transitioning afterpending tasks have been processed when the status information indicatesthat the other storage unit is associated with pending rebuilding ordata access tasks. The method continues at step 524 where the processingmodule issues and activation status change request to the selected otherstorage unit, where the request includes the transition approach and anindicator to deactivate the selected other storage unit.

FIG. 44 is a flowchart illustrating an example of enabling slicerebuilding, which includes similar steps to FIG. 43B. The methodcontinues with steps 512-516 of FIG. 43B where a processing module(e.g., of a distributed storage and task network (DSTN) managing unit)obtains status information for a set of storage units, selects a storageunit associated with an inactive status for reactivation in accordancewith a rotation scheme and based on the status information, and issuesan activation status change request to the selected storage unit.

The method continues at step 526 where the processing module receives anactivation status change response from the selected storage unit thatindicates detected slice errors and required candidate in active storageunits to facilitate rebuilding encoded data slices associated with thedetected slice errors. As a specific example, the selected storage unitscans for the slice errors and issues the activation status changeresponse after determining that a decode threshold number of otherstorage units are not available to facilitate rebuilding.

The method continues at step 528 where the processing module selects oneor more other storage units associated with an inactive status forreactivation based on the required candidate in active storage units andin accordance with a rotation scheme. As a specific example, theprocessing module selects a storage unit that is scheduled forreactivation soon in accordance with the rotation scheme that isincluded in the required candidate in active storage units. The methodcontinues at step 530 where the processing module issues and activationstatus change request to the one or more other storage units requestingreactivation.

The method continues with step 518 of FIG. 43B where the processingmodule receives an activation status change response from the selectedstorage unit (e.g., after rebuilding). The method continues at step 532where the processing module obtains updated status information for theset of storage units. When the activation status change responseincludes an indication that rebuilding has been completed, the methodcontinues at step 534 where the processing module selects at least oneof the one or more other storage units for deactivation in accordancewith the rotation scheme and the updated status information. As aspecific example, the processing module selects the other storage unitwhere the other storage unit is associated with no pending rebuildingtasks for the selected storage unit.

The method continues at step 536 where the processing module determinesa transition approach for the selected at least one storage unit basedon the updated status information. As a specific example, the processingmodule indicates the transition approach to be immediately sincerebuilding has been completed for the selected storage unit. As anotherspecific example, the processing module indicates the transitionapproach to be after processing of the rebuilding tasks associated withother storage units. The method continues at step 538 where theprocessing module issues an activation status change request of the atleast one storage unit, where the request includes the transitionapproach.

FIG. 45A is a schematic block diagram of another embodiment of adispersed storage network (DSN) that includes a plurality of userdevices 550, a plurality of dispersed storage (DS) processing modules552, and a DSN memory 554. The DSN memory 554 includes a plurality of DSunits 556. The DS units 556 may be organized into one or more sets of DSunits. Each DS unit 556 may be implemented utilizing the distributedstorage and task (DST) execution unit 36 of FIG. 1. Each DS processingmodule 552 may be implemented utilizing the DST processing unit 16 ofFIG. 1 each user device 550 may be implemented utilizing one or more ofthe user device 14 and the user device 12 of FIG. 1.

The system functions to access a data object in the DSN memory 554 inaccordance with a data de-duplication approach. The accessing includesstoring, retrieving, and deleting. In an embodiment, the DS processingmodule 552, when operable within a computing device, causes thecomputing device to perform a series of steps. In an example ofoperation of the steps, when the accessing of the data object includesstoring the data object, the user device 550 issues a store data request558 to a DS processing module 552 to store the data object in the DSNmemory 554, where the store data request 558 includes one or more of adata object, data identifier (ID) of a plurality of data IDs associatedwith the data object, and a data tag (e.g., a result of performing adeterministic function on at least a portion of the data object). Forexample, a subsequent store data request from another user device 550 ofthe plurality of user devices may also include the data object (e.g.,identical to the data object from the user device) and another data IDassociated with the data object.

Having received the store data request 558, the DS processing module 552generates a source name (e.g., a DSN address) for the received dataobject based on one or more of the data ID, a vault ID, and a requestingentity ID. Having generated the source name, the DS processing module552 determines whether the data object has already been stored in theDSN memory 554. The determining includes one or more of generating adata tag for the received data object, comparing the generated data tagto a list of data tags associated with data objects stored in the DSNmemory 554, comparing the received data tag to the list of data tags,and comparing the received data object to data objects stored in the DSNmemory 554.

When the data is not already stored in the DSN memory 554, the DSprocessing module 552 issues a write object request 560 to the DSNmemory 554 using the source name to store the received data object inthe DSN memory 554. The issuing of the write object request 560 includesencoding the data object using a dispersed storage error coding functionto produce a plurality of sets of encoded data slices, generating aplurality of sets of slice names using the source name, generating oneor more sets of write slice requests that includes the plurality of setsof encoded data slices and the plurality of sets of slice names, andoutputting the one or more sets of write slice requests as the writeobject request 560 to a set of DS units 556 of the DSN memory 554. Inaddition, the DS processing module 552 may store the data tag and one ormore of the data ID, the source name, the vault ID, and the requestingentity ID in one or more of the list of data tags, a hierarchicaldispersed index, and a directory.

When the data object is already stored in the DSN memory 554, the DSprocessing module 552 obtains location information of a previouslystored data object that compares favorably to the received data objectand issues a write link-object request 562 to the DSN memory 554 thatincludes the location information. The location information includes atleast one of a DSN address corresponding to the previously stored dataobject, a source name of the previously stored data object, and aplurality of sets of slice names corresponding to the previously storeddata object. The issuing of the link-object request 562 includesencoding the link-object using the dispersed storage error codingfunction to produce a set of encoded link-object slices, generating aset of slice names using the source name, generating a set of writeslice requests that includes the encoded link-object slices and the setof slice names, and outputting the set of write slice requests to theset of DS units 556 of the DSN memory 554. In addition, the DSprocessing module 552 may store the data tag and one or more of the dataID, the source name, the vault ID, and the requesting entity ID in oneor more of the list of data tags, the hierarchical dispersed index, andthe directory.

In accordance with the data de-duplication approach, when the accessingof the data object includes retrieving the data object, another userdevice 550 (e.g., any user device of the plurality of user devices)issues a read data request 564 to the DS processing module 552 toretrieve the data object stored in the DSN memory 554, where the readdata request 564 includes another data ID associated with the dataobject. The DS processing module 552 retrieves another source nameassociated with the data object based on the other data ID. Theregenerating includes retrieving the other source name from at least oneof the hierarchical dispersed index, the directory, and the list of datatags. The DS processing module 552 issues a primary read request 566 tothe DSN memory 554 using the other source name (e.g., generate a set ofslice names using the other source name, generate a set of read slicerequests that includes the set of slice names, output the set of readslice requests to the DSN memory as the primary read request 566). TheDS processing module 552 receives a primary read response 568 from theDSN memory 554 (e.g., receiving at least a decode threshold number ofslices, decoding the at least a decode threshold number of slices toproduce a recovered object).

The DS processing module 552 determines whether the recovered object ofthe primary read response 568 includes a first data segment of the dataobject or of the link-object. The determining includes identifying aformat of the recovered object (e.g., indicate data object when therecovered object includes data, indicate link-object when the objectincludes the location information. When the primary read response 568includes the link-object, the DS processing module 552 issues asecondary read request 570 to the DSN memory 554 to retrieve the dataobject. The issuing includes generating a plurality of sets of slicenames based on the source name of the previously stored data object,generating one or more sets of read slice requests that includes theplurality of sets of slice names, outputting the one or more sets ofread slice requests as the secondary read request 570 to the set of DSunits 556 of the DSN memory 554, receiving a secondary read response 572that includes, for each data segment of a plurality of data segments ofthe data object, at least a decode threshold number of encoded dataslices, for each data segment, decoding the at least a decode thresholdnumber of encoded data slices to reproduced the data segment, andaggregating a plurality of reproduce data segments to reproduce the dataobject.

When the primary read response includes the first data segment of thedata object, the DS processing module 552 issues the secondary readrequest 570 to the DSN memory 554 to retrieve subsequent data segmentsof the plurality of data segments of the data object. The issuingincludes generating a remaining plurality of sets of slice names basedon the source name of the previously stored data object, generating oneor more sets of read slice requests that includes the remainingplurality of sets of slice names, outputting the one or more sets ofread slice requests as the secondary read request 570 to the set of DSunits 556 of the DSN memory 554, receiving a secondary read response 572that includes, for each remaining data segment of the plurality of datasegments of the data object, at least a decode threshold number ofencoded data slices, for each remaining data segment, decoding the atleast a decode threshold number of encoded data slices to reproduce theremaining data segment, and aggregating the first data segment of thedata object with a plurality of reproduced remaining data segments toreproduce the data object. Having reproduced the data object, the DSprocessing module 552 issues a read data response 574 to the user device550, where the read data response 574 includes the reproduced dataobject.

In accordance with the data de-duplication approach, when the accessingof the data object includes deleting the data object, the other userdevice 552 (e.g., any user device of the plurality of user devices)issues a delete data request 576 to the DS processing module 552 todelete the data object stored in the DSN memory 554, where the deletedata request 576 includes any data ID associated with the data object.The DS processing module 552 identifies metadata associated with thedata object and updates the metadata to indicate that one less copy isstored in the DSN memory 554. When the data ID is associated with alink-object, the DS processing module 552 deletes the link-object fromthe DSN memory 554. When no further copies are stored of the dataobject, a DS processing module 552 deletes the data object and themetadata from the DSN memory 554. The method to delete data is discussedin greater detail with reference to FIGS. 45B and 45C.

From time to time, the DS processing module 552 may perform a deletescanning operation to rationalize a number of copies of the data objectand a number of link-objects stored in the DSN memory. For example, themetadata may indicate a higher number of copies of the data when alink-object previously stored in the DSN memory 554 is missing. The DSprocessing module 552 identifies the copies of the data object (e.g., byissuing primary read requests 566, receiving primary read responses 568,and interpreting the primary read responses 568 to identify link-objectsas the copies). Next, the DS processing module 552 determines a numberof copies of the data object based on a number of link-objectsidentified. The DS processing module 552 obtains the metadata of thedata object of the data ID and compares a number of copies from themetadata to the number of link-objects identified. When the number oflink-objects identified does not match the number of copies from themetadata, the DS processing module 552 indicates that a potential copyerror has been detected. The method to detect the potential copy erroris discussed in greater detail with reference to FIGS. 45B and 45C.

FIG. 45B is a schematic block diagram of another embodiment of adispersed storage network that includes the dispersed storage (DS)processing module 552 of FIG. 45A, the memory 88 of FIG. 3, and thedispersed storage network (DSN) memory 554 of FIG. 45A. The DSN memory554 includes the plurality of DS units 556 of FIG. 45A. Hereafter, eachDS unit may be referred to interchangeably as a storage unit of a set ofstorage units.

The system functions to access a data object in the DSN memory 554 inaccordance with a data de-duplication approach. In an embodiment, the DSprocessing module 552, when operable within a computing device, causesthe computing device to perform a series of steps. In an example ofoperation of the steps, the DS processing module 552 determines whethera change has occurred to a data object of a set of data objects, whereeach data object of the set of data objects has substantially identicaldata to other data objects of the set of data objects and where only oneplurality of sets of encoded data slices corresponding to one dataobject 578 of the set of data objects is stored in the DSN memory 554using the right object request 560 of FIG. 45A.

The change includes at least one of addition of an identified dataobject of the set of data objects and deletion of the identified dataobject. The determining includes at least one of receiving the storedata request 558 of FIG. 45A and receiving the delete data request 576of FIG. 45A. For example, the DS processing module 552 indicates thatthe change includes the addition of the identify data object whenreceiving the store data request 558, where the store data request 558includes the identified data object that has substantially identicaldata to other data objects stored in the DSN memory 554. As anotherexample, the DS processing module 552 indicates that the change includesthe deletion of the identified data object when receiving the deletedata request 576.

When a change has occurred, the DS processing module 552 accessesde-duplication tracking data 582 for the set of data objects. Forexample, the DS processing module 552 retrieves the de-duplicationtracking data 582 from the memory 88. As another example, the DSprocessing module 552 recovers the de-duplication tracking data 582 fromthe DSN memory 554. The de-duplication tracking data 582 includes arepresentation of the substantially identical data 584, addressinginformation 580 for the only one plurality of sets of encoded dataslices (e.g., corresponding to the one data object 578), and linkinginformation 586 that links the set of data objects to the addressinginformation 580. The representation of the substantially identical data584 includes a hashed representation of the data object.

When the change is the addition of the identified data object of the setof data objects, the DS processing module 552 generates a linking objectfor linking DSN addressing of the identified data object to theaddressing information 580. As a specific example, the DS processingmodule 552 extracts the identified data object from the store datarequest 588, generates a DSN address for the identified data object(e.g., a DSN address for accessing the linking object), and generates alinking object 2 that includes the addressing information of the onedata object 580.

Having generated the linking object, the DS processing module 552updates the linking information 586 to include a representation of thelinking object. As a specific example, the DS processing module 552increments a count of data objects in the set of data objects. Asanother specific example, the DS processing module 552 updates thelinking information 586 to include the linking object 2. Having updatedthe linking information 586, the DS processing module 552 facilitatestorage of the linking object in the DSN memory 554. For example, the DSprocessing module 552 issues the write link-object request 562 of FIG.45A to the DSN memory 554, where the write link-object request 562includes a set of encoded data slices generated based on the linkingobject 2.

When the change is deletion of the identified data object of the set ofdata objects, the DS processing module 552 determines whether theidentified data object is the only data object in the set of dataobjects. For example, the DS processing module 552 identifies a numberof copies from the linking information 586. When the identified dataobject is not the only data object in the set of data objects, the DSprocessing module 552 updates the linking information 586 to deletelinking the identified data object to the addressing information 580. Asa specific example, the DS processing module 552 decrements the numberof copies of the link information 586. As another specific example, theDS processing module 552 deletes an associated linking object from thelinking information 586. When the identified data object is the onlydata object in the set of data objects, the DS processing module 552issues a command to delete the only one plurality of sets of encodeddata slices and deletes the de-duplication tracking data 582 from thememory 88. For example, the DS processing module 552 issues anotherwrite object request 560 to the DSN memory 554, where the other writeobject request 560 includes a deletion instruction for the one dataobject 578.

The DS processing module 552 may, from time to time, rationalize thenumber of copies of the data object. In an example of operation, the DSprocessing module 552 identifies a plurality of linking objects storedin the DSN memory 554. The identifying includes at least one ofsearching a DSN directory, searching a dispersed hierarchical index, andinterpreting the de-duplication tracking data 582. Having identified theplurality of linking objects stored in the DSN memory 554, the DSprocessing module 552 determines a count of linking objects of theplurality of linking objects that are associated with the set of dataobjects. For example, the DS processing module 552 increments atemporary count by one for each identified linking object.

Having determined the count of linking objects, the DS processing module552 compares the count of linking objects to a count of the linkingobjects of the linking information 586. When the count of linkingobjects compares unfavorably to the count of the linking objects of thelinking information 586, the DS processing module 552 updates thelinking information based on a discrepancy between the count of linkingobjects and the count of the linking objects of the linking information586.

The method described above in conjunction with the DS processing module552 can alternatively be performed by other modules of the dispersedstorage network, of a distributed storage and task network or by otherdevices. In addition, at least one memory section that storesoperational instructions that can, when executed by one or moreprocessing modules of one or more computing devices of a dispersedstorage network (DSN), cause the one or more computing devices toperform any or all of the method steps described above.

FIG. 45C is a flowchart illustrating an example of updatingde-duplication tracking data. The method continues at step 600 where aprocessing module (e.g., of one or more processing modules of one ormore computing devices of a dispersed storage network (DSN)) determineswhether a change has occurred to a data object of a set of data objects.Each data object of the set of data objects has substantially identicaldata to other data objects of the set of data objects. Only oneplurality of sets of encoded data slices corresponds to one data objectof the set of data objects is stored in memory of the DSN.

When a change has occurred, the method continues at step 602 where theprocessing module accesses de-duplication tracking data for the set ofdata objects. The de-duplication tracking data includes a representationof the substantially identical data, addressing information for the onlyone plurality of sets of encoded data slices, and linking informationthat links the set of data objects to the addressing information. Themethod branches to step 608 when the change includes deletion. Themethod continues to step 604 when the change includes addition.

When the change is addition of an identified data object of the set ofdata objects, the method continues at step 604 where the processingmodule generates a linking object for linking DSN addressing of theidentified data object to the addressing information. The methodcontinues at step 606 where the processing module updates the linkinginformation to include a representation of the linking object. Forexample, the processing module increments a count of data objects in theset of data objects. As another example, the processing module updatesthe linking information to include the linking object. The methodbranches to step 614.

When the change is deletion of an identified data object of the set ofdata objects, the method continues at step 608 where the processingmodule determines whether the identified data object is the only dataobject in the set of data objects. The method branches to step 612 whenthe identified data object is the only data object. The method continuesto step 610 when the identified data object is not the only data object.

When the identified data object is not the only data object in the setof data objects, the method continues at step 610 where the processingmodule updates the linking information to delete linking the identifieddata object to the addressing information. The method branches to step614. When the identified data object is the only data object in the setof data objects, the method continues at step 612 where the processingmodule issues a command to delete the only one plurality of sets ofencoded data slices and deletes the de-duplication tracking data. Themethod branches to step 614.

The method continues at step 614 where the processing module identifiesa plurality of linking objects stored in the memory of the DSN. Themethod continues at step 616 where the processing module determines acount of linking objects of the plurality of linking objects that areassociated with the set of data objects. The method continues at step618 where the processing module compares the count of linking objects toa count of the linking objects of the linking information. When thecount of linking objects compares unfavorably to the count of thelinking objects of the linking information, the method continues at step620 where the processing module updates the linking information based ona discrepancy between the count of linking objects and the count of thelinking objects of the linking information.

FIG. 46A is a schematic block diagram of an embodiment of a dispersedstorage network that includes a dispersed storage (DS) processing module552 and two or more dispersed storage network (DSN) storage pools (e.g.,622-1, 622-2, 622-3 and 622-4). Each DSN storage pool 622 includes a setof DS units 556. Each DS unit 556 may be the distributed storage andtask (DST) execution unit 36 of FIG. 1 and further contain memory 88(e.g., hard drives or flash memory as shown in, for example, FIG. 3 andFIG. 11). The DS processing module 552 may be the DST processing unit 16of FIG. 1. The system functions to store data in any of the DSN storagepools 622 with selection of specific storage pool DS units 556 based ona logical mapping (e.g., first four units in each of storage pool 1 andstorage pool 2 with enough capacity for the storage group). In alternateembodiments, selection of specific storage pool DS units 556 may bebased on a specific methodology or criteria of mapping DS units withinthe storage pool groups (e.g., needed speed, type of memory, type ofdata, DS unit capacities, frequency of access, generation of storagedrives, number of users within storage group, etc.)

In an example of operation, the DS processing module issues storageutilization queries 1-2 to the DSN storage pools 1-2. At least one DSunit 556 of each DSN storage pool 622 issues a storage utilizationresponse to the DS processing module that includes an indication of oneor more of unutilized storage space (e.g., free space) for each storagegroup, utilized storage space for each storage group, total utilizedstorage space, total unutilized storage space as well as, in oneembodiment, metadata about one or more storage units serviced by one ormore DS units 556. The storage group includes an association with one ormore of a vault, a portion of a vault, and a vault region, where thevault includes a logical association of virtual storage, mapped DS unitsand of storage utilization entities.

In one example, a storage group requires very fast, high capacitystorage (e.g., ultra high definition (UHD) video data). A combination ofutilization information retrieved (available capacity) during thestorage utilization queries as well as available metadata describingspecific DS unit storage (average access speed, generation, etc.) willassist in selection of specific DS units 556 for one or more pools. Asshown, storage pool 1 includes four DS units (1-1, 1-2, 1-3 and 1-4)with storage/access to memory 88 (e.g., hard drives—FIG. 11) matchingthe requirements. Storage pool 2 includes two DS units (2-15 and 2-16)with storage/access to memory 88 (e.g., hard drives—FIG. 11) matchingthe same requirements. Therefore, the first four DS units in storagepool 1 (1-1, 1-2, 1-3 and 1-4) and the last two DS units in storage pool2 (2-15 and 2-16) are selected to support the storage group. Specificallocation of future write requests (i.e., write proportions) in the sixmapped DS units (1-1, 1-2, 1-3, 1-4, 2-15 and 2-16) of the storage groupwill be described in greater detail in association with FIGS. 46C and46D.

In another example, a storage group includes logically interlaced datafor storage/retrieval (e.g., television image data). FIG. 46C includes astorage group mapping of odd DS units of storage pool 3 and even DSunits for storage pool 4. For example, the odd numbered DS units instorage pool 3 (1-1, 1-3, etc.) and the even numbered units in storagepool 4 (4-2, 4-4, etc.) are selected to support the storage group.Specific allocation of future write requests (i.e., write proportions)will follow the described systems and methods as shown and described inassociation with FIGS. 46C and 46D.

While the above examples include specific DS unit selections, themapping of a specific number (e.g., 4, 5, 10, 16, etc.) of DS units fora storage group is not limiting as disclosed herein. Any combination ofDS units (e.g., all, zero, or a subset combination), from one or morestorage pools, is envisioned without departing from the scope of thepresent invention.

FIG. 46B is a flowchart illustrating an example of selecting and mappingDS units within two or more storage pools of a storage group. The methodbegins at step 624 where a processing module (e.g., of a dispersedstorage (DS) processing module) selects storage pools within the DSNwith available capacity for storage of storage group data. Capacitiesare determined, for example, by queries to two or more dispersed storagenetwork (DSN) storage pools of a DSN, where each DSN storage poolincludes a set of DS units as will be described in greater detailhereafter.

The method continues in step 626, where the available capacities andmetadata (if available) of the DS units within storage pools iscollected by DS processing module 552. The method continues at step 628,where DS unit selection criteria is determined. DS unit selectioncriteria may be determined by the DS processing module 552 processinginformation associated with a storage group such as, but not limited to,one or more of: data type; capacity requirements; access frequency; datastorage retrieval formats; data retrieval sequencing; required speed;and number of users within storage group; and information associatedwith the one or more DS units including one or more of: type of memory(disk/flash/tape); error rates; age of memory; and maintenance historyof memory, etc.

The method continues in step 630, where DS units are selected and mappedto a storage group based on the determined DS unit selection criteriaand one or more DS units meeting the selection criteria (e.g., 6 DSunits from one pool and 10 DS units from a second pool meet thecriteria).

The method continues at step 632 where the processing module receives awrite request to store a data object in the DSN. In step 634, theprocessing module identifies a storage group of the one or more storagegroups, where the storage group is associated with a write request. TheDS processing module identifies the storage group based on one or moreof a data type, a requesting entity identifier, a data identifier, avault identifier associated with the data identifier, and a vault regionidentifier associated with the data identifier.

The method continues at step 636 where the processing module facilitatesstoring the data object in the selected DSN storage pool and mapped DSunits.

FIG. 46C is a schematic block diagram of another embodiment of adispersed storage network that includes a dispersed storage (DS)processing module 552 and two or more dispersed storage network (DSN)storage pools 622-1, 622-2, 622-N. Each DSN storage pool 622 includes aset of DS units 556. Each DS unit 556 may be the distributed storage andtask (DST) execution unit 36 of FIG. 1. The DS processing module 552 maybe the DST processing unit 16 of FIG. 1. The system functions to storedata in the DSN storage pools 622.

In an example of operation, the DS processing module issues storageutilization queries 1-2 to the DSN storage pools 1-2. At least one DSunit 556 of each DSN storage pool 622 issues a storage utilizationresponse to the DS processing module that includes an indication of oneor more of unutilized storage space for each storage group, utilizedstorage space for each storage group, total utilized storage space, andtotal unutilized storage space. The storage group includes anassociation with one or more of a vault, a portion of a vault, and avault region, where the vault includes a logical association of virtualstorage, mapped DS units and storage utilization entities. For example,the DSN storage pools stored data associated with a first and secondstorage group.

The issuing of the storage utilization response includes determiningutilized storage 640 and unutilized storage 642 space for each storagegroup 638. The DS unit sums slice lengths of all encoded data slicesthat are stored in the DS unit associated with each storage group todetermine utilized storage space for each storage group. As a specificexample, a first DS unit (1-1) of DSN storage pool 1 (622-1) identifies9 GB of utilized storage associated with a first storage group and 1 GBof utilized storage associated with a second storage group. As anotherspecific example, a first DS unit (2-1) of DSN storage pool 2 (622-2)identifies 4 GB of utilized storage associated with the first storagegroup and 0 GB of utilized storage associated with the second storagegroup (e.g., storage group 2 is not stored in the DSN storage pool 2).

The DS unit identifies total unutilized storage space (e.g., adifference between storage capacity and total utilized storage space ofall storage groups) and pro-rates the total unutilized storage spaceamongst each storage group proportionate to the utilized storage spacefor each storage group to determine the unutilized storage space foreach storage group. As a specific example, the first DS unit (1-1) ofDSN storage pool 1 (622-1) identifies 1 GB of total unutilized storagespace (e.g., a capacity of 11 GB−10 GB of total utilize storage space)and multiplies a ratio of 9 GB/10 GB times the 1 GB=0.9 GB of unutilizedstorage space for storage group 1 and multiplies a ratio of 1 GB/10 GBtimes the 1 GB=0.1 GB of unutilized storage space for storage group 2for DSN storage pool 1. As another specific example, the first DS unitof DSN storage pool 2 identifies 8 GB of total unutilized storage space(e.g., a capacity of 12 GB−4 GB of total utilize storage space) andmultiplies a ratio of 4 GB/4 GB times the 8 GB=8 GB of unutilizedstorage space for storage group 1 and multiplies a ratio of 0 GB/4 GBtimes the 8 GB=0 GB of unutilized storage space for storage group 2 forDSN storage pool 2.

The DS processing module receives at least one storage utilizationresponse from each DSN storage pool. The DS processing module updates awrite proportion value based on the received storage utilizationresponses. The updating includes reestablishing the write proportionbased on an amount of unutilized storage space for each storage groupsuch that new writes to a given storage group are directed to a DSNstorage pool in proportion to the amount of unutilized storage space. Asa specific example, for storage group 1, the write proportion value isupdated to select DSN storage pool 1 0.9/(0.9+8) % of the time and toselect DSN storage pool 2 8/(0.9+8) % of the time period.

The DS processing module receives a write request to store a new dataobject in the DSN. The DS processing module identifies a storage groupfor the write request based on one or more of a data type of the newdata object, a requesting entity identifier, a DSN address, a vaultidentifier, and a vault region identifier. As a specific example, the DSprocessing module identifies storage group 1 based on the requestingentity identifier. Having identified the storage group, the DSprocessing module selects a DSN storage pool based on the writeproportion value and a recent write pattern of previous DSN storage poolselections. As a specific example, the DS processing module identifiesDSN storage pool 2 based on the recent write pattern and the writeproportion value of 8/(0.9+8) %. The DS processing module facilitatesstoring the new data object in the selected DSN storage pool. As aspecific example, the DS processing module encodes the new data objectusing a dispersed storage error coding function to produce sets ofencoded data slices and issues sets of write slice requests 1 to the DSNstorage pool 1, where the sets of write slice requests 1 includes thesets of encoded data slices. The method of operation to store theencoded data slices based on the write proportion value is discussed ingreater detail with reference to FIG. 46B.

The DS processing module may receive a storage utilization response thatindicates that a storage group is fully utilized within a particular DSNstorage pool. The DS processing module may indicate that no unutilizedstorage space for the storage group is available to prevent furtherstoring of new encoded data slices to the DSN storage pool for thestorage group. Alternatively, the DS processing module may indicate thata predetermined minimum amount of unutilized storage space for thestorage group is available to enable processing of write slice requestswithout encoded data slices by DS units of the DSN storage pool tofacilitate deletion of previously stored encoded data slices whilepreventing further storing of new encoded data slices to the DSN storagepool for the storage group. The method of operation to enable deletionof previously stored encoded data slices is discussed in greater detailwith reference to FIG. 47.

FIG. 46D is a flowchart illustrating an example of selecting a storagepool. The method begins at step 644 where a processing module (e.g., ofa dispersed storage (DS) processing module) issues storage utilizationqueries to two or more dispersed storage network (DSN) storage pools ofa DSN, where each DSN storage pool includes a set of DS units (e.g.,previously mapped). The issuing includes generating and sending. Themethod continues at step 646 where at least one DS unit of each DSNstorage pool issues a storage utilization response. The issuingincludes, for each storage group, the DS unit determining unutilizedstorage space for the storage group in accordance with a formula:unutilized storage space for the storage group=unutilized storage spacefor all storage groups*(utilized storage space for the storagegroup/utilize storage space for all storage groups). The DS unitgenerates the storage utilization response to include one or more of theunutilized storage space and utilize storage space of each storage groupand sends the storage utilization response to the processing module.

The method continues at step 648 where the processing module updates awrite proportion value for one or more storage groups based on receivedstorage utilization responses. As a specific example, the processingmodule updates the write proportion value for a particular storage groupto include an indication to select a storage pool in accordance with aselection formula of: select a storage pool as a percentage of allselections=unutilized space for the storage group of the storagepool/all unutilized space for the storage group of all storage pools.

The method continues at step 650 where the processing module receives awrite request to store a data object in the DSN. In step 652, theprocessing module identifies a storage group of the one or more storagegroups, where the storage group is associated with a write request. TheDS processing module identifies the storage group based on one or moreof a data type, a requesting entity identifier, a data identifier, avault identifier associated with the data identifier, and a vault regionidentifier associated with the data identifier.

The method continues at step 654 where the processing module selects aDSN storage pool of the two or more DSN storage pools based on the writeproportion value and a recent write pattern. The selecting includesidentifying the recent write pattern, selecting the DSN storage pool inaccordance with the write pattern so that the DSN storage pool isselected at the write proportion value for the storage group overprevious writes. The selecting may further include verifying thatsufficient unutilized space is greater than space required facilitatesstoring the data object. The method continues at step 656 where theprocessing module facilitates storing the data object in the selectedDSN storage pool.

FIG. 47 is a flowchart illustrating an example of facilitating deletinga data object, which includes similar steps to FIG. 46D. The methodbegins with step 644 of FIG. 46D where a processing module (e.g., of adispersed storage (DS) processing module) issues a storage utilizationqueries to two or more dispersed storage network (DSN) storage pools ofa DSN, where each DSN storage pool includes a set of DS units. Themethod continues with step 646 where a DS unit of each DSN storage poolissues a storage utilization response. The method continues at step 702where the processing module identifies a storage group of an associatedDSN storage pool with zero unutilized storage space based on a receivedstorage utilization response.

The method continues at step 704 where the processing module indicatesthat the identified storage group is write-restricted for the DSNstorage pool to not support write requests associated with storing dataand to support write requests associating with deleting data. Theindicating includes updating a locally stored copy of the receivedstorage utilization response to indicate that the storage group has apredetermined minimal amount of unutilized storage space to facilitatedeletion of data but not to facilitate storing of new data.

The method continues at step 706 where the processing module receives awrite request to store a data object in the DSN using the identifiedstorage group. As a specific example, the processing module receives astore data request and identifies the storage group associated with thedata of the request. When the identified storage group iswrite-restricted, the method continues at step 708 where the processingmodule issues a write response indicating that writing is restricted tothe DSN storage pool. Alternatively, or in addition to, the processingmodule identifies an alternative DSN storage pool associated with thestorage group that is write-restricted. The issuing includes verifyingthe identified storage group is restricted for the DSN storage pool, andgenerating and sending the write response to a requesting entity.

The method continues at step 710 where the processing module receives adelete request to delete another data object associated with theidentified storage group associated with the DSN storage pool. When theidentified storage group is write-restricted for the DSN storage pool,the method continues at step 712 where the processing module facilitatesdeleting the other data object. The facilitating includes generatingwrite slice requests that includes slice names associated with the otherdata object but does not include encoded data slices (e.g., a null in anencoded data slice field of each write slice request). The facilitatingfurther includes sending the write slice requests for deleting the otherdata object to the DSN storage pool associated with thewrite-restriction of the storage group.

FIG. 48A is a schematic block diagram of another embodiment of adispersed storage network that includes a distributed storage and task(DST) client module 34 and a set of DST execution units 36 of the DSTexecution units 36 of FIG. 1. Each DST execution unit 36 includes theprocessing module 84 and one or more memories 88 of FIG. 3. The networkfunctions to store data in the set of DST execution units 36. The DSTexecution units 36 function to store the data as sets of encoded dataslices in the memories 88 of the DST execution units 36 in accordancewith a slice location optimization.

In an example of operation utilizing the slice location optimization, aprocessing module 84 of a first DST execution unit 36 receives a seriesof slice access requests 802, processes the series of slice accessrequests, and issues slice access responses 804 to the DST client module34. Each access request includes one of a write request, a read request,a delete request or a list request.

The processing the series of slice access requests includes theprocessing module 84 generating time stamped slice access records toinclude identities of encoded data slices and identities of associatedmemories 88 of the series of processed slice access requests. As aspecific example, the processing module 84 generates a first sliceaccess record to include encoded data slice identifiers A_1 through A_N(e.g., data A, common pillar slices of segments 1-N) were accessed in afirst memory 88-1 in a first timeframe. As yet another specific example,the processing module 84 generates a second slice access record toinclude encoded data slice identifiers B_1 through B_N were accessed ina second memory 88-2 in a second timeframe. As a still further specificexample, the processing module 84 generates a third slice access recordto include encoded data slice identifier C_1 was accessed in the secondmemory 88-2 in a third timeframe and also encoded data slice identifiersC_2 through C_N were accessed in a third memory 88-3 in the thirdtimeframe.

With the access records stored, the processing module 84 determinescorrelation of two or more slice access sequences (e.g.,request-response) based on the access records. As a specific example,the processing module 84 identifies a correlation of the accessing ofencoded data slice C_1 and encoded data slices C_2 through C_N in thethird timeframe. As another specific example, the processing module 84identifies that there is a 95% probability that encoded data slice C_1will be accessed from the second memory 88-2 within 5 seconds ofaccessing encoded data slices C_2 through C_N from the third memory88-3. The processing module 84 determines whether the correlation of thetwo or more slice access sequences is greater than a correlationthreshold level. As a specific example, the processing module indicatesthat the correlation is greater than the correlation threshold levelwhen the correlation is 95% and the correlation threshold level is 70%.

When the correlation of the two or more slice access sequences isgreater than the correlation threshold level, the processing module 84identifies two or more encoded data slices for co-location. Theco-location includes one or more of storing the two or more encoded dataslices within a common memory device, in adjacent storage locationswithin the common memory device, in similar storage locations within thecommon memory device, in a common virtual storage container tofacilitate co-reading, in a common stripe across at least two memorydevices, etc. The processing module 84 determines whether the two ormore encoded data slices for co-location are not co-located (e.g., bycomparing associated memory devices and storage locations). As aspecific example, the processing module 84 determines that the encodeddata slice C_1 is not co-located with encoded data slices C_2 throughC_N.

When the two or more encoded data slices for co-location are notco-located, the processing module 84 selects one or more of the two ormore encoded data slices for migration to a new storage locationassociated with the co-location. The selecting may be based on one ormore of current storage locations, memory device associations of the oneor more encoded data slices for migration, available memory devicecapacity, and available storage locations. As a specific example, theprocessing module 84 selects encoded data slice C_1 for migration whenencoded data slices C_2 through C_N are already stored together on thethird memory device 88-3.

With the one or more encoded data slices selected for migration, theprocessing module 84 selects a co-location method to support theco-location. The selecting may be based on one or more of thecorrelation of the two or more encoded data access sequences, thecorrelation threshold level, the available memory capacity, theavailable storage locations, a memory device performance level, DSTexecution unit processing resource availability, a DST execution unitloading level, a predetermination, the current storage locations, andthe memory device associations of the one or more encoded data slicesfor migration. For example, the processing module 84 selects theco-location method to include storing the two or more encoded dataslices within similar storage locations of a common memory device. As aspecific example, the processing module 84 selects storing encoded dataslices slice C_1 and encoded data slices C_2 through C_N within adjacentas possible storage sectors of the third memory device 88-3 (e.g., whenmemory device 88-3 is implemented using a magnetic disk storagetechnology).

With the co-location method selected, the processing module 84facilitates migration of the selected one or more encoded data slices inaccordance with the co-location method. As a specific example, theprocessing module 84 moves encoded data slice C_1 from the second memory88-2 to a storage sector of the third memory 88-3 that is substantiallyadjacent to storage sectors utilized for storage of encoded data slicesC_2 through C_N. The processing module 84 updates a slice name tostorage location table to associate encoded data slice C_1 with thestorage sector of the third memory 88-3.

FIG. 48B is a flowchart illustrating an example of co-locatingassociated encoded data slices. The method begins at step 806 where aprocessing module (e.g., of a distributed storage and task (DST)execution unit) monitors DST execution unit slice access requests togenerate access records. The monitoring includes receiving accessrequests, generating timestamps to associate with access records, andgenerating the access records to include associating identities of theencoded data slices of the access requests and the timestamps. Themethod continues at the step 808 where the processing module correlatestwo or more slice access requests based on the access records to producea correlation value. For example, the processing module determines aprobability of processing two or more slice access requests within agiven timeframe to produce a probability as the correlation value. Theprocessing module determines whether the correlation value is greaterthan a correlation threshold level.

When the correlation value is greater than the correlation thresholdlevel, the method continues at step 810 where the processing moduleidentifies two or more encoded data slices for co-location. Theidentifying includes identifying the two or more encoded data slicesassociated with a correlation value greater than a selection threshold.The processing module determines whether the two or more encoded dataslices for co-location are not stored utilizing a common storageconfiguration. The common storage configuration includes one or more ofa common memory device, adjacent sectors on a magnetic disk drive,similar sectors on the magnetic disk drive, and a common virtual storagecontainer, a common stripe across two or more memory devices, etc.

When the two or more encoded data slices for co-location are not storedutilizing the common storage configuration, the method continues at step812 where the processing module selects one or more of the two or moreencoded data slices for migration to the common storage configuration.The selecting includes at least one of identifying a fewest number ofencoded data slices requiring migration and identifying a greatestnumber of encoded data slice not requiring migration that are alreadyassociated with the common storage configuration.

The method continues at step 814 where the processing module determinesthe common storage configuration based on the access records. Thedetermining includes at least one of identifying the common storageconfiguration of the greatest number of encoded data slices notrequiring migration, utilizing a predetermination, and determining a newstorage configuration to facilitate sufficient storage capacity for allof the two or more encoded data slices. The method continues at step 816where the processing module migrates the selected one or more encodeddata slices to the common storage configuration. As a specific example,the processing module moves encoded data slices to adjacent sectors of acommon magnetic disk memory device.

FIG. 48C is a flowchart illustrating an example of co-locatingassociated encoded data slices. The method begins at step 818 where aprocessing module (e.g., of a distributed storage and task (DST)execution unit) monitors DST execution unit slice access requests togenerate access records. The monitoring includes receiving accessrequests and generating the access records to include associating commonslice names (identities) of the encoded data slices of the accessrequests. The method continues at the step 820 where the processingmodule correlates two or more slice access requests based on the accessrecords to produce a correlation value. For example, the processingmodule determines a probability of processing two or more slice accessrequests with slice name commonality to produce a probability as thecorrelation value. The processing module determines whether thecorrelation value is greater than a correlation threshold level.

When the correlation value is greater than the correlation thresholdlevel, the method continues at step 822 where the processing moduleidentifies two or more encoded data slices for co-location. Theidentifying includes identifying the two or more encoded data slicesassociated with a correlation value greater than a selection threshold.The processing module determines whether the two or more encoded dataslices for co-location are not stored utilizing a common storageconfiguration. The common storage configuration includes one or more ofa common memory device, adjacent sectors on a magnetic disk drive,similar sectors on the magnetic disk drive, and a common virtual storagecontainer, a common stripe across two or more memory devices, etc.

When the two or more encoded data slices for co-location are not storedutilizing the common storage configuration, the method continues at step824 where the processing module selects one or more of the two or moreencoded data slices for migration to the common storage configuration.The selecting includes at least one of identifying a fewest number ofencoded data slices requiring migration and identifying a greatestnumber of encoded data slice not requiring migration that are alreadyassociated with the common storage configuration.

The method continues at step 826 where the processing module determinesthe common storage configuration based on the access records. Thedetermining includes at least one of identifying the common storageconfiguration of the greatest number of encoded data slices notrequiring migration, utilizing a predetermination, and determining a newstorage configuration to facilitate sufficient storage capacity for allof the two or more encoded data slices. The method continues at step 830where the processing module migrates the selected one or more encodeddata slices to the common storage configuration. As a specific example,the processing module moves encoded data slices to adjacent sectors of acommon magnetic disk memory device.

While the embodiments of FIGS. 48B and 48C describe time and namecommonality, respectively, as elements which associate data which couldbe co-located, other elements which establish an association(relationship) between slices of data which are not co-located can be,in other embodiments, be substituted without departing from the scope ofthe present invention.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

As may also be used herein, the terms “processing module”, “processingcircuit”, and/or “processing unit” may be a single processing device ora plurality of processing devices. Such a processing device may be amicroprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module, module, processingcircuit, and/or processing unit may be, or further include, memoryand/or an integrated memory element, which may be a single memorydevice, a plurality of memory devices, and/or embedded circuitry ofanother processing module, module, processing circuit, and/or processingunit. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static memory, dynamicmemory, flash memory, cache memory, and/or any device that storesdigital information. Note that if the processing module, module,processing circuit, and/or processing unit includes more than oneprocessing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

The present invention has been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention. Further, theboundaries of these functional building blocks have been arbitrarilydefined for convenience of description. Alternate boundaries could bedefined as long as the certain significant functions are appropriatelyperformed. Similarly, flow diagram blocks may also have been arbitrarilydefined herein to illustrate certain significant functionality. To theextent used, the flow diagram block boundaries and sequence could havebeen defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claimed invention. One of average skill in the artwill also recognize that the functional building blocks, and otherillustrative blocks, modules and components herein, can be implementedas illustrated or by discrete components, application specificintegrated circuits, processors executing appropriate software and thelike or any combination thereof.

The present invention may have also been described, at least in part, interms of one or more embodiments. An embodiment of the present inventionis used herein to illustrate the present invention, an aspect thereof, afeature thereof, a concept thereof, and/or an example thereof. Aphysical embodiment of an apparatus, an article of manufacture, amachine, and/or of a process that embodies the present invention mayinclude one or more of the aspects, features, concepts, examples, etc.described with reference to one or more of the embodiments discussedherein. Further, from figure to figure, the embodiments may incorporatethe same or similarly named functions, steps, modules, etc. that may usethe same or different reference numbers and, as such, the functions,steps, modules, etc. may be the same or similar functions, steps,modules, etc. or different ones.

While the transistors in the above described figure(s) is/are shown asfield effect transistors (FETs), as one of ordinary skill in the artwill appreciate, the transistors may be implemented using any type oftransistor structure including, but not limited to, bipolar, metal oxidesemiconductor field effect transistors (MOSFET), N-well transistors,P-well transistors, enhancement mode, depletion mode, and zero voltagethreshold (VT) transistors.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of the various embodimentsof the present invention. A module includes a processing module, afunctional block, hardware, and/or software stored on memory forperforming one or more functions as may be described herein. Note that,if the module is implemented via hardware, the hardware may operateindependently and/or in conjunction software and/or firmware. As usedherein, a module may contain one or more sub-modules, each of which maybe one or more modules.

While particular combinations of various functions and features of thepresent invention have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent invention is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A method for execution by one or more processingmodules of one or more computing devices of a dispersed storage network(DSN), the method comprises: sending a set of low retention prioritywrite requests to storage units of the DSN, wherein each low retentionpriority write request of the set of low retention priority writerequests includes a low retention priority query; for each storage unitof the storage units that receives a low retention priority writerequest of the set of low retention priority write requests: determininga low retention priority response regarding availability for storing lowretention priority data based on current storage of low priority dataobjects and available memory for storing the low retention prioritydata; and sending the low retention priority response; and when athreshold number of favorable low retention priority responses have beenreceived, facilitating storage of a low retention priority data object.2. The method of claim 1 further comprises: including a set of encodeddata slices within the set of low retention priority write requests whensending the set of low retention priority write requests, wherein a datasegment of the low retention priority data object is dispersed storageerror encoded to produce the set of encoded data slices; and for eachstorage unit of the storage units that receives a low retention prioritywrite request of the set of low retention priority write requests:determining whether there is available memory for storing the lowretention priority data; when there is not available memory for storingthe low retention priority data, comparing retention priority of anencoded data slice of another low retention priority data object of thecurrent storage of low priority data objects with a retention priorityof an encoded data slice of the set of encoded data slices; and when theretention priority of the encoded data slice of the set of encoded dataslices compares favorably to the retention priority of the encoded dataslice of the other low retention priority data object: overwriting theencoded data slice of the other low retention priority data object withthe encoded data slice of the set of encoded data slices; and sending awrite response.
 3. The method of claim 2, wherein the facilitating thestorage of the low retention priority data object comprises: sending aset of write commit requests to each storage unit sending the writeresponse.
 4. The method of claim 2, wherein the determining whetherthere is available memory for storing the low retention priority datacomprises: determining total available memory within the storage unit;determining a level of storage of higher priority data objects; anddetermining whether there is available memory for storing the lowretention priority data based on the total available memory and thelevel of storage the higher priority data objects.
 5. The method ofclaim 1 further comprises: the facilitating storage of the low retentionpriority data object by sending, for storage, a set of encoded dataslices to the storage units providing the favorable low retentionpriority response, wherein a data segment of a low retention prioritydata object is dispersed storage error encoded to produce the set ofencoded data slices; and for each storage unit receiving an encoded dataslice of the set of encoded data slices: determining whether there islow retention priority memory currently available; when the lowretention priority memory is not currently available, comparingretention priority of an encoded data slice of another low retentionpriority data object of the current storage of low priority data objectswith a retention priority of an encoded data slice of the set of encodeddata slices; and when the retention priority of the encoded data sliceof the set of encoded data slices compares favorably to the retentionpriority of the encoded data slice of the other low retention prioritydata object: overwriting the encoded data slice of the other lowretention priority data object with the encoded data slice of the set ofencoded data slices; and sending a write response.
 6. The method ofclaim 1 further comprises: generating the low retention priority queryto include queries regarding different levels of low retention prioritydata; for a given low retention priority level of the low retentionpriority data object to be stored, determining whether the thresholdnumber of favorable low retention priority responses have been received;and when the threshold number of favorable low retention priorityresponses have been received for the given low retention priority level,facilitating the storage of the low retention priority data object.
 7. Amethod for execution by a storage unit of a dispersed storage network(DSN), the method comprises: receiving a low retention priority writerequest of a set of low retention priority write requests to storageunits of the DSN, wherein the low retention priority write requestincludes a low retention priority query; determining a low retentionpriority response regarding availability for storing low retentionpriority data based on current storage of low priority data objects andavailable memory for storing the low retention priority data; sendingthe low retention priority response; and receiving, from a computingdevice, a write facilitating request regarding storage of a portion of alow retention priority data object when the computing device received athreshold number of favorable low retention priority responses.
 8. Themethod of claim 7 further comprises: receiving an encoded data slice ofa set of encoded data slices within the low retention priority writerequest, wherein a data segment of a low retention priority data objectis dispersed storage error encoded to produce the set of encoded dataslices; determining whether there is available memory for storing thelow retention priority data; when there is not available memory forstoring the low retention priority data, comparing retention priority ofan encoded data slice of another low retention priority data object ofthe current storage of low priority data objects with a retentionpriority of an encoded data slice of the set of encoded data slices; andwhen the retention priority of the encoded data slice of the set ofencoded data slices compares favorably to the retention priority of theencoded data slice of the other low retention priority data object:overwriting the encoded data slice of the other low retention prioritydata object with the encoded data slice of the set of encoded dataslices; and sending a write response.
 9. The method of claim 8, whereinthe determining whether there is available memory for storing the lowretention priority data comprises: determining total available memorywithin the storage unit; determining a level of storage of higherpriority data objects; and determining whether there is available memoryfor storing the low retention priority data based on the total availablememory and the level of storage the higher priority data objects. 10.The method of claim 7 further comprises: interpreting the low retentionpriority query to identify queries regarding different levels of lowretention priority data; for a given low retention priority level of thelow retention priority data object to be stored, determining whether thethreshold number of favorable low retention priority responses have beenreceived; and when the threshold number of favorable low retentionpriority responses have been received for the given low retentionpriority level, facilitating storage of the low retention priority dataobject.
 11. A computer readable storage medium comprises: at least onememory section that stores operational instructions that, when executedby one or more processing modules of one or more computing devices of adispersed storage network (DSN), causes the one or more computingdevices to: send a set of low retention priority write requests tostorage units of the DSN, wherein each low retention priority writerequest of the set of low retention priority write requests includes alow retention priority query; for each storage unit of the storage unitsthat receives a low retention priority write request of the set of lowretention priority write requests: determine a low retention priorityresponse regarding availability for storing low retention priority databased on current storage of low priority data objects and availablememory for storing the low retention priority data; and send the lowretention priority response; and when a threshold number of favorablelow retention priority responses have been received, facilitate storageof a low retention priority data object.
 12. The computer readablestorage medium of claim 11 further comprises: the at least one memorysection stores further operational instructions that, when executed bythe one or more processing modules, causes the one or more computingdevices of the DSN to: include a set of encoded data slices within theset of low retention priority write requests when sending the set of lowretention priority write requests, wherein a data segment of the lowretention priority data object is dispersed storage error encoded toproduce the set of encoded data slices; and for each storage unit of thestorage units that receives a low retention priority write request ofthe set of low retention priority write requests: determine whetherthere is available memory for storing the low retention priority data;when there is not available memory for storing the low retentionpriority data, compare retention priority of an encoded data slice ofanother low retention priority data object of the current storage of lowpriority data objects with a retention priority of an encoded data sliceof the set of encoded data slices; and when the retention priority ofthe encoded data slice of the set of encoded data slices comparesfavorably to the retention priority of the encoded data slice of theother low retention priority data object: overwrite the encoded dataslice of the other low retention priority data object with the encodeddata slice of the set of encoded data slices; and send a write response.13. The computer readable storage medium of claim 12, wherein the one ormore processing modules functions to execute the operationalinstructions stored by the at least one memory section to cause the oneor more computing devices of the DSN to facilitate the storage of thelow retention priority data object by: sending a set of write commitrequests to each storage unit sending the write response.
 14. Thecomputer readable storage medium of claim 12, wherein the one or moreprocessing modules functions to execute the operational instructionsstored by the at least one memory section to cause the one or morecomputing devices of the DSN to determine whether there is availablememory for storing the low retention priority data object by:determining total available memory within the storage unit; determininga level of storage of higher priority data objects; and determiningwhether there is available memory for storing the low retention prioritydata based on the total available memory and the level of storage thehigher priority data objects.
 15. The computer readable storage mediumof claim 11 further comprises: the at least one memory section storesfurther operational instructions that, when executed by the one or moreprocessing modules, causes the one or more computing devices of the DSNto: facilitate the storage of the low retention priority data object bysending, for storage, a set of encoded data slices to the storage unitsproviding the favorable low retention priority response, wherein a datasegment of a low retention priority data object is dispersed storageerror encoded to produce the set of encoded data slices; and for eachstorage unit receiving an encoded data slice of the set of encoded dataslices: determine whether there is low retention priority memorycurrently available; when the low retention priority memory is notcurrently available, compare retention priority of an encoded data sliceof another low retention priority data object of the current storage oflow priority data objects with a retention priority of an encoded dataslice of the set of encoded data slices; and when the retention priorityof the encoded data slice of the set of encoded data slices comparesfavorably to the retention priority of the encoded data slice of theother low retention priority data object: overwrite the encoded dataslice of the other low retention priority data object with the encodeddata slice of the set of encoded data slices; and send a write response.16. The computer readable storage medium of claim 11 further comprises:the at least one memory section stores further operational instructionsthat, when executed by the one or more processing modules, causes theone or more computing devices of the DSN to: generate the low retentionpriority query to include queries regarding different levels of lowretention priority data; for a given low retention priority level of thelow retention priority data object to be stored, determine whether thethreshold number of favorable low retention priority responses have beenreceived; and when the threshold number of favorable low retentionpriority responses have been received for the given low retentionpriority level, facilitate the storage of the low retention prioritydata object.
 17. A storage unit of a dispersed storage network (DSN),the storage unit comprises: an interface; and a processing moduleoperable to: receive, via the interface, a low retention priority writerequest of a set of low retention priority write requests to storageunits of the DSN, wherein the low retention priority write requestincludes a low retention priority query; determine a low retentionpriority response regarding availability for storing low retentionpriority data based on current storage of low priority data objects andavailable memory for storing the low retention priority data; send, viathe interface, the low retention priority response; and receive, from acomputing device via the interface, a write facilitating requestregarding storage of a portion of a low retention priority data objectwhen the computing device received a threshold number of favorable lowretention priority responses.
 18. The storage unit of claim 17 furthercomprises: the processing module is further operable to: receive, viathe interface, an encoded data slice of a set of encoded data sliceswithin the low retention priority write request, wherein a data segmentof a low retention priority data object is dispersed storage errorencoded to produce the set of encoded data slices; determine whetherthere is available memory for storing the low retention priority data;when there is not available memory for storing the low retentionpriority data, compare retention priority of an encoded data slice ofanother low retention priority data object of the current storage of lowpriority data objects with a retention priority of an encoded data sliceof the set of encoded data slices; and when the retention priority ofthe encoded data slice of the set of encoded data slices comparesfavorably to the retention priority of the encoded data slice of theother low retention priority data object: overwrite the encoded dataslice of the other low retention priority data object with the encodeddata slice of the set of encoded data slices; and send, via theinterface, a write response.
 19. The storage unit of claim 18, whereinthe storage unit functions to determine whether there is availablememory for storing the low retention priority data by: determining totalavailable memory within the storage unit; determining a level of storageof higher priority data objects; and determining whether there isavailable memory for storing the low retention priority data based onthe total available memory and the level of storage the higher prioritydata objects.
 20. The storage unit of claim 17 further comprises: theprocessing module is further operable to: interpret the low retentionpriority query to identify queries regarding different levels of lowretention priority data; for a given low retention priority level of thelow retention priority data object to be stored, determine whether thethreshold number of favorable low retention priority responses have beenreceived; and when the threshold number of favorable low retentionpriority responses have been received for the given low retentionpriority level, facilitate storage of the low retention priority dataobject.